Evolutionary Psychology | Chapter 14

14 Evolutionary Psychology and Culture Key Concepts superorganic cultural transmission evoked culture transmitted culture dual-inheritance theory gene–culture co-evolution culturegens memes and memetics imitation cultural drive The study...

14 Evolutionary Psychology and Culture Key Concepts superorganic cultural transmission evoked culture transmitted culture dual-inheritance theory gene–culture co-evolution culturegens memes and memetics imitation cultural drive The study of culture is usually the preserve of social anthropologists, sociologists and cultural the- orists who have developed sophisticated theories to describe and explain cultural phenomena. Re- cently, there has been much interest in an evolutionary approach to culture. In contrast to many earlier theories these evolutionary theories attempt to provide ultimate rather than proximate expla- nations of culture. One of the biggest ultimate questions about culture is why do we have culture at all? From this perspective, the phenomenon of culture is not something that ‘just happened’; there is good evidence that human culture needs a particular sort of brain in order to sustain it. Therefore, there is a distinct possibility that the emergence of culture conferred some advantage to our ances- tors in terms of their inclusive fitness (see Chapters 2 and 7). In addition to ultimate questions, evo- lutionists have also asked proximate questions. What, for example, are the cognitive processes that are necessary to enable the transmission of culture, what psychological factors can lead to changes in cultural practices and what is the relationship between culture and genes? The following chapter addresses these and other questions in exploring the relationship between evolution and culture. The Importance of Culture Human beings have come a long way in a remarkably short time. In a mere 11,000 years or so – the blink of an eye by evolutionary standards – we have gone from living in small hunter-gatherer communities with primitive artefacts to vast liberal democracies with intensive agriculture, writing, mass education and Twitter. Eleven thousand years is generally regarded as too short a time for our brains to have changed significantly, so the difference between us and our ancestors is unlikely to be a result of changes in our mental hardware (the brain). Rather it seems that these differences are due to continual changes in software – the knowledge that we have acquired and the practices that this knowledge informs. These repeated software upgrades come courtesy of other people through the process of cultural transmission. That culture has had such a large influence can mislead us into thinking that culture has nothing to do with evolution or our biological inheritance. It is easy to imagine evolution and biol- ogy as entirely separate forces that mould us into our current shape, and that an understanding of biology cannot help us to understand the nature of culture. Both of these arguments have been con- tested by recent cultural theorists. First, as we shall see, some theorists argue that cultural practices – 390 Evolutionary Psychology and Culture variable though they might seem – are not completely arbitrary; rather they are influenced by a human nature shaped by natural selection. Second, the very process of cultural transmission – our ability and desire to imitate others – is underpinned by specialised neural mechanisms that were likely to have been produced by evolution. As we shall see, although imitation is often considered crude, it is a much more complex skill than first meets the eye. Before presenting evolutionary theories of culture, we begin by discussing some of the earlier ideas about culture, in particular the notion that culture, far from being constrained by human nature, is an autonomous force that shapes the way we behave. Culture as ‘Superorganism’ The majority of research studying culture has tended to focus on trying to explain cultural differ- ences, and this was something that certainly preoccupied the thoughts of the Victorians. Why, they asked, do we in the West have agriculture, steel tools and democracy whereas people in other parts of the world live a hunter-gatherer existence, with stone tools and lack organised politics? To the eyes of many Victorians the difference was clearly the result of innate, biological differences be- tween the people who inhabit these societies. Many considered the so-called savages to be incapable of logical thought and some regarded them as a separate species altogether. The zoologist Ernst Haeckel (1834–1919), for example, proposed that ‘natural men are closer to the higher vertebrates than to highly civilised Europeans’. This way of thinking was turned on its head by anthropologist Franz Boas (1852–1942). Instead of explaining cultural variation in terms of innate psychological differences between people, Boas proposed that behaviour needed to be understood in terms of culture. It was culture that caused the psychological differences, not the other way round. Nowadays this is an uncontroversial claim and one with which the overwhelming majority of psychologists (including evolutionary psycholo- gists) concur. Apart from a few, notable exceptions, which we discuss later in this chapter, there is no Figure 14.1 Samoan girls playing cards around the time that Mead visited the island.  The Importance of Culture 391 evidence that cultural differences are reducible to genetic differences; as we saw in Chapter 6, children easily adopt the culture of the environment in which they grow up irrespective of their genetic origins. Once culture had been identified as a force that can shape human behaviour, some fol- lowers of Boas set about presenting it as the only significant influence of human behaviour. One of Boas’ students, anthropologist Alfred Kroeber, argued that culture was superorganic; that it existed as an autonomous force free from human influence. Sociologist Ellsworth Faris summed up this position when he wrote in 1927 that: Instincts do not create customs; customs create instincts, for the putative instincts of hu- man beings are always learned, never native. (quoted in Degler, 1991, 161) In the early part of the twentieth century Margaret Mead, another of Boas’ students, wrote a number of influential books taken as demonstrating the flexibility of human culture. In Coming of Age in Samoa (1928) she describes how the attitudes of adolescent girls to sex and marriage were very different from those of girls in contemporary Western society. In particular she claimed that un- married Samoan adolescents had a much more liberal attitude towards sex than their counterparts in 1920s Europe and America. In other works, she described the Tchambuli tribe (whose name has subsequently been standardised as the Chambri, which we use here) where the sex roles were appar- ently reversed. Chambri women were the breadwinners whereas the men seemed to spend their time engaged in what were seen as traditional female roles such as painting and dancing. Partly inspired by Mead, anthropological research exploded, with globetrotting researchers unearthing cultures that were seemingly diametrically opposed to what was considered the norm by Westerners. By the 1950s it seemed that no practices were culturally universal; it appeared that any cultural practice that we might imagine could be found to exist – so long as we looked in the right place. These and other examples of the variety of human culture seem to support the notion that culture is indeed superorganic. As Mead (1935) argued: We are forced to conclude that human nature is almost unbelievably malleable, responding accurately and contrastingly to contrasting cultural conditions. (280) The notion of culture as a superorganic force that shapes human behaviour is part of what Tooby and Cosmides call the Standard Social Sciences Model (SSSM) or alternatively cultural relativism and was adopted by many social scientists from Mead’s time to the present day (see Pinker, 2002, for a review of the prevalence of this style of thinking). Recently the superorganic view of culture has come under attack on a number of fronts. First, some of the evidence supporting this view has been challenged (see Box 14.1) and second, evidence has been presented that, far from culture being autonomous and infinitely variable, there are a number of ‘cultural universals’. Cultural Universals – the ‘Universal People’ Anthropologist Donald Brown (1991) describes a number of cultural norms and practices that seem to exist in all cultures studied. Brown describes the origins of his enterprise as the result of a discussion with evolutionary psychologist and anthropologist Donald Symons, who argued for the universality of certain sex differences. As an anthropologist from the cultural relativist school, Brown did not believe in cultural universals and bet Symons that he could find a culture in which each of Symons’ proposed universal sex differences was reversed. He didn’t win the bet. In fact, he completely revised his opinions. After studying a large number of cultures Brown discovered that there were more than 200 characteristics (now around 350; Pinker, 2002) common to all cultures 392 Evolutionary Psychology and Culture including characteristics as diverse as burial rituals, logical operators, sex role differentiation, incest taboos, rituals surrounding food, dance, metaphorical speech, tool making, wariness of snakes, classification of colour and thumb sucking. This work suggests that rather than being infinitely variable human cultures are in fact strikingly similar when viewed from a suitably abstract level. Universality is not, however, in itself conclusive evidence for innateness; good ideas tend to spread from culture to culture (known as idea diffusion). Pottery and agriculture, for example, appear in the overwhelming majority of societies, but no one would argue that there are innate mental modules for throwing pots or tilling the soil. But universals might be the starting point for research on innate aspects of culture, especially when such practices seem unlikely to have arisen by idea diffusion (by virtue of their isolation many of the cultures studied by Brown had no opportunities to acquire traits from other cultures). Box 14.1 Re-evaluating Margaret Mead Margaret Mead’s work was one of the cornerstones of the superorganic view of culture and has recently been the subject of a great deal of criticism. Anthropologist Derek Freeman (see Free- man, 1983) has written several excoriating critiques of her work. Freeman argues that Mead was opposed to biological and evolutionary approaches to the study of human behaviour and culture, and that she interpreted her data in order to repudiate such an approach. He also claims that some of Mead’s data were questionable, that she was at best misled by some of the subjects of her research and at worst culpable of exaggeration and fabrication. Freeman argues that Mead’s Samoan adolescents enjoyed making up stories about their sexual liberation, and Mead, perhaps because she wanted to believe them, failed to seek corroborative evidence for their stories. However, in Mead’s defence, anthropologist Paul Shankman (1998) proposes that, far from being an anti-evolutionist, Margaret Mead saw human behaviour as being both culturally and biologically determined. He argues that in the early years of her academic life, Mead did indeed embrace a form of cultural malleability and even cultural determinism, but her views matured to embrace a more multi-factorial view of human behaviour. For instance, in 1961 she expressed concern that the influence of genetics research on anthropology was principally in the sub-dis- cipline of physical anthropology and urged her fellow social anthropologists to investigate their role in social behaviour. More generally she spoke of ‘the opportunity provided by the new upsurge of interest in the whole field of evolution, in which human evolution is one part and cultural evolution a smaller one’ (481). Mead was involved in the sociobiology controversy (see Chapter 1); in his autobiography E. O. Wilson (1994) recounts how at a meeting of the American Anthropological Association in 1976 Mead protested against an attempt to officially censure so- ciobiology. Intriguingly, in her own autobiography Mead intimates that at least one of the reasons for her extreme cultural relativism was political: We knew how politically loaded discussions of inborn differences could become. … [I]t seemed clear to us that [their] further study … would have to wait upon less troubled times. (Mead, 1972, 222) Mead was certainly not an evolutionist, but it seems that in her later writings she recognised the importance of evolution as a motivating force in the shaping of human behaviour. Of course, as is the case with many great figures, it is her earlier rather than her later work with which she has become most closely associated.  Culture and Social Learning 393 Culture and Social Learning Fundamentally culture involves two processes: innovation and copying, and the most important is copying. It’s great to have a great idea, but if no one notices it will usually die. To be part of culture the great idea needs to be taken up, bought into, adopted, embraced and endorsed; innovations drive culture, but copying is what makes an innovation part of culture. It may or may not surprise you to learn that many animals are able to copy, and not just large-ish animals such as parrots, apes and dogs, but smaller, more overlooked species such as fruit flies and sticklebacks (Mery et al., 2009; Pike and Laland, 2010). But none copy with quite the facility of humans. This was beautifully re- vealed by the work of psychologists Winthrop and Luella Kellogg (Kellogg and Kellogg, 1933), who conducted an experiment in which they reared an infant chimpanzee named Gua alongside their similar aged son Donald. They were interested in whether the chimp would become more human if reared in a similar manner to a human child. Gua was made to wear clothes and shoes, was allowed to run free round the house, was bathed, potty trained and generally treated just like a normal infant. Gua and Donald got on very well playing together just like two siblings of similar age. Gua was also ahead of Donald in a variety of developmental tests that Winthrop Kellogg devised. She was able to feed herself with a spoon earlier and was better able than her human counterpart to use a chair to reach a biscuit that had been suspended from the ceiling. But, at least in the early years be- fore Donald acquired language, there was one thing that Donald beat Gua at hands down: he was the better imitator. Rather worryingly for his parents, Donald would imitate Gua’s chimpanzee food bark and it was Gua, rather than Donald, who usually took the lead in finding new things to do, Donald generally just copied her. What this story reveals is just how good humans – even infant humans – are at imitating the behaviour of others, even when those others might not be the best role models. Why Are Humans Such Good Imitators? On the face of it, copying does not seem to be a particularly intelligent act and indeed many of the words we use to describe imitation are pejorative, we talk of doing things ‘parrot fashion’, of ‘verbatim regurgitation’, ‘plagiarism’ and of one person ‘aping’ another. Interestingly, although we use the verb ‘ape’ to describe mindless copying, the Kelloggs’ research suggests that humans are somewhat better at aping than are apes! Recently, many researchers have come to see the importance of imitation in human development and as an essential component of the development of culture. There is considerable debate, however, as to what imitation is. Psychologist E. L. Thorndike’s definition as ‘learning to do an act from seeing it done’ (Thorndike, 1898, 50) is a good enough defini- tion but this includes a variety of behaviours that vary in complexity. For example, many simple forms of apparent imitation can be explained by a process known as stimulus enhancement (see Byrne and Russon, 1998). Stimulus enhancement is simply the tendency of an animal to pay attention to an object or area as a result of seeing some other animal achieve some success with that object or in that area. An animal that goes to a food patch after seeing another animal successfully exploit it might be ex- plained by stimulus enhancement. But this seems quite different from an animal deliberately imitating the actions of another (such as potato washing in Japanese Macaques; Kawai, 1965; see Box 14.2). Box 14.2 Do Non-human Animals Have Culture? The debate as to whether other animals possess culture is strongly reminiscent of other debates such as whether animals have language, or whether other animals use tools. On the one side, given that we 394 Evolutionary Psychology and Culture Box 14.2 (cont.) relatives the apes – must have it too. Such a line of reasoning is not necessarily correct. There are many instances in the natural world where one species has a unique adaptation. The classic example is the elephant’s trunk. No other animal has an organ anything like as sophisticated as this flexible, delicate and at the same time immensely strong organ. This is not because the trunk evolved in some massive leap of evolution, it is because all of the elephant’s close relatives have died out. Likewise, there is no reason to rule out the notion that we might be alone in the natural world in having a culture. Of course, as with all such debates (see Chapter 10) it depends on how we define culture. Clear- ly, no other animal has the breadth of technological innovation that is present in human cultures, but what about a more modest definition of culture as a system of transmitted behaviours; is there any evidence that non-human animals have culture in these terms? Some have observed innovations spreading through populations of primates. In 1952 (Kawai, 1965) on Koshima island a group of sci- entists studying the social behaviour of Japanese macaques (an old-world primate; see Figure 14.2) attracted the primates towards them by throwing sweet potatoes on the ground. Initially the macaques wiped the dust and sand off the potatoes by wiping them with their hands, then one day a juvenile female known as Imo took her potatoes to the water’s edge and washed them clean. This washing behaviour spread through the population so that by 1958 14 of the 15 juveniles and 2 of the 11 adults washed potatoes. Other examples where novel behaviours are apparently transmitted through a pop- ulation are the use of twigs to catch termites in chimpanzees (Goodall, 1964), birdsong (Jenkins, 1978) and fear of snakes in rhesus monkeys (Mineka and Cook, 1988). Furthermore, research on the common chimpanzee (Pan troglodytes; see Chapter 4) reveals that there is substantial variation across the different groups that is reminiscent of the human cultural variation (Whiten et al., 1999). The authors describe 39 variations in behaviours including grooming, tool use and courtship. The distribution of these behaviours suggests that they are transmitted culturally rather than genetically. For example, nut-cracking behaviour terminates at the boundary of the Sassandra-N’Zo river, even though the chimps on either side are close genetic relatives. Field data suggest that chimpanzees imitate each other (particularly more senior chimps and parents) in the use of tools and the execution of behaviours. A group of chimps known as Taï chimps use a rock as an anvil and a stone or wooden ‘hammer’ in order to crack nuts, a behaviour that young chimps seem to learn from adults. A differ- ent group, the Gombe chimps, are unable to crack nuts, even though they are in plentiful supply. The observation that behaviours vary when the environment does not (in this case the presence of nuts) tends to rule out the claims that variation is simply due to variation in environmental opportunity. The observations that chimps learn by imitation are supported by experimental research, demon- strating that chimps imitate each other when opening novel artificial ‘fruits’ (Whiten, 1998). Not everyone believes that animals have culture. Many claim that the research outlined above is the result of genetic variation in behavioural traits, or the results of environmental pres- sures forcing animals to adapt one or other strategy. Others protest that although chimps (and other animals) might be able to learn new behaviours from each other and pass these on to their offspring, this does not constitute culture. Nagell et al. (1993) present evidence that while human children are able to imitate the method by which a particular goal was achieved (in this case reaching an object with a rake) chimpanzees arrive at the same goal by many means, irrespective of the behaviour shown to them. Nagell et al. refer to this as learning by emulation rather than imitation. Imitation requires the individual to mentally represent the intention of the actor and thereby see the method as a means of achieving this goal. In emulation, on the other hand, the  Evolutionary Theories of Culture 395 Figure 14.2 Japanese macaques love to make snowballs (anoth- er cultural practice). Comparative research by Nagell et al. (1993) indicates that, although adult chimpanzees are able to imitate a human in using a rake to retrieve an out-of-reach object, they are only able to do this to the level of a two-year-old child. Even the positive examples of cultural transmission in non-human primates – such as food washing in Japanese macaques – spread quite slowly through a population of a few tens of individuals. In a human population of equal size the innovation would have spread like wildfire. Tomasello argues that one reason humans have such complex culture is that they are better than other animals at identifying with their conspecifics. Primates seem to be alone in the animal kingdom in being able to represent the mental states of their conspecifics; when they observe ac- tions, they are able to infer what the animal’s intentions are behind the action. This is important in imitation since it gives meaning to the actions; without being able to figure out why someone is doing what they are doing the actions will seem meaningless. According to Tomasello, an important reason why humans are better at imitating than other primates such as chimps is that they are better able to represent the goals and intentions of other people; they have a more sophisticated theory of mind (see Chapter 5). To see why this is important, imagine that an animal observes a conspecific poking a stick into the ground. If that animal has a sophisticated theory of mind it can use it to infer that the individual’s goal in using the stick is to obtain food – termites. Armed with this knowledge the animal can then decide whether or not to imitate this action and, crucially, to apply it only in situations where there are known to be termites. Without this ability to infer intention all that is seen is the poking action with no knowledge of why it is being done. In this case there is no reason why the animal should imitate and even if it did, it is likely that the poking action would be deployed in a random way because the animal has no knowledge of its purpose. Evolutionary Theories of Culture Evoked versus Transmitted Culture Above we described the existence of cultural universals as suggesting that certain aspects of culture might be constrained by human nature. However, according to 396 Evolutionary Psychology and Culture cultural variability among cultural elements should not be taken as suggesting that human nature plays no role in their existence. They coined the term evoked culture to describe cultural practices that might arise as a result of mental modules that are environmentally contingent (they contrast this with transmitted culture which are the result of factors such as imitation, modelling and idea diffusion). For example, the life history theory of attachment presented in Chapter 6 suggests that high-risk environments might lead individuals to adopt strategies that maximise current reproduc- tive gain, whereas low-risk environment might lead to strategies that maximise future reproductive gain. The variability here might be seen as the result of parameter setting in an evolved module which is sensitive to specific environmental cues such as parental investment. This is analogous to Chomsky’s claim that the language module sets parameters (such as whether a language is sub- ject–verb–object or verb–subject–object) based on the child’s minimal experience of the linguistic environment. Thus, a contingent universal exists only if some other condition (or conditions) is present in the environment and might thus give rise to variability (we discussed this idea in Chapter 13). Currently research into these contingent universals is sparse and some researchers (including Boyd and Richerson, whom we discuss next) are sceptical as to their utility in explaining human be- haviour. However, contingent universals and evoked cultures are important areas for future research and may add to the already large number of universals that we presented above. Dual-Inheritance Theory and the Evolution of Culture Biologist Robert Boyd and anthropologist Peter Richerson (Boyd and Richerson, 1985; Richerson and Boyd, 2001; Boyd, Richerson and Henrich, 2011) propose that in humans, and perhaps some other animals, the mind (and thus behaviour) is produced by two interacting modes of inheritance: genes and culture. Their theory enables researchers to model the effects of genes on culture (the reductionist approach despised by many psychologists and anthropologists) but also the effects that culture has on genes (see Tomasello, 1999, and later in this chapter). Biological evolution is slow. It takes a human between 12 and 16 years to reach sexual maturity, which sets an upper limit of between six and eight generations every hundred years. By comparison some viruses and bacteria can produce offspring at a rate that is measured in minutes. Of course, and as we saw in Chapter 3, humans have the advantage of sexual rather than asexual reproduction to produce greater variability in offspring and thus speed evolution along but, even taking this into account, biological evolution is a painfully slow process. As we pointed out above, biologically speaking, the bodies of twenty-first-century humans seem to have changed little in the past 100,000 years or so (Mourre and Henshilwood, 2010) – a period in which human culture has, for most people, changed beyond recognition. Culture, therefore, doesn’t just benefit us by provid- ing us with specific practices, skills and artefacts; it benefits us by enabling us to change our behav- iour extremely rapidly to fit environmental conditions. Boyd and Richerson argue that this potential for rapid adaptation is one reason why the mind evolved an ability to generate and sustain culture. Imagine that the temperature dropped dramatically in some part of the world. Many organ- isms, ill equipped by natural selection to cope with the cooler temperatures, might freeze to death unless cold-resistant mutations arise. Humans, with their second mode of inheritance, can develop new ways of combating the cold such as by wearing animal skins, and pass such technologies on to their offspring, enabling them too to survive. This process of ‘technological inheritance’ is crucial. In many mammalian species individuals will learn new ways of coping with the environment (usu- ally by trial and error or by lucky accident), but without the ability to pass these on to their offspring the innovations will die with their creator.  Evolutionary Theories of Culture 397 Culture therefore enables humans to ‘evolve’ (adapt to the environment) at a faster rate than would be possible if we relied simply on biological evolution, but cultural transmission works as an adaptive strategy only under certain conditions. Mathematical models suggest that in order for cultural transmission to be beneficial the environment must have changed at a particular rate. If the environment changed too rapidly, then knowledge held by one generation would be of little use to the next generation. Under such conditions it would be futile for parents to pass their knowledge on to their children and it would make more sense for each generation to learn for themselves. If, on the other hand, the environment changed too slowly then genetic change could keep up and there would have been no need for the metabolically costly brains that are required to maintain culture. It seems that the time that modern human beings started to appear coincides with the environmental conditions that Boyd and Richerson claim are optimal for cultural transmission to be adaptive. During the Pleistocene period there was a significant degree of environmental change. There were several ice ages lasting tens of thousands of years, and there were also more local chang- es with temperatures varying dramatically over periods of a few thousand years. These temperature changes would have had direct and indirect effects on our ancestors. The direct effects would have included the effects of extreme cold on the human body, necessitating different forms of clothing, shelter and dietary requirements. The indirect effects would have been the changes in vegetation and animal populations that could inhabit the particular regions, which would have required different hunting and gathering techniques. Both of these effects would have meant that the ability to pass on new technologies and practices via cultural transmission would have been advantageous to those capable of doing so. This is, however, circumstantial, as Boyd and Richerson freely admit, and does not count as conclusive evidence for their theory of why the ability to acquire culture evolved. Boyd and Richerson also speculate on the evolution of the specifics of culture – the par- ticular practices and values adopted by a group of individuals. They propose that cultural practic- es can evolve by a process akin to group selection (but only cultural practices, they are adamant that biological processes are not shaped by group selection; see Chapter 2). In their view, different cultures can be seen in competition with the successful culture being the one whose practices are passed on to the next ‘generation’. For example, one tribe might destroy another as a result of war (perhaps because their war-making cultural technologies are more effective; see Diamond’s research discussed later). Alternatively the ‘weaker’ tribe might not be killed outright but might be captured and have the dominant culture forced upon them (language, practices, religions etc.). Or the ‘weak- er’ tribe might simply adopt the cultural practices of another perhaps because the people recognise that they are superior to their own (Richerson and Boyd, 2005). Thus, although the ability to acquire culture (and perhaps some of the universals described above) might be the result of an evolved hu- man nature, evolutionary processes might also account for the spread of ‘learned culture’ albeit by a process of group selection. Gene–Culture Co-evolution Above we discussed arguments concerning ‘universal people’ and evoked culture which suggests that genes might directly or indirectly affect cultural practices. A consequence of dual-inheritance theory is that cultural practices can affect genetic evolution. Sociobiologists Charles Lumsden and E. O. Wilson (1981) developed a theory known as gene–culture co-evolution in which genes and culture are seen as intimately entwined and co-dependent. They argue that humans have innate learning capacities which make some cultural elements easier to learn than others, with the result that they are more likely to become established in the culture (Lumsden and Wilson, 1981). The 398 Evolutionary Psychology and Culture close relationship between culture and biology espoused by Lumsden and Wilson was best summed up by Wilson (1978) when he stated: The genes hold culture on a leash. The leash is very long but inevitably values will be con- strained in accordance with their effects on the human gene pool. (167) Lumsden and Wilson focus on the process of epigenesis, the interaction between genes and the environment that occurs during development (see Chapter 2). They proposed that epigenetic rules embody certain biological imperatives (behaviours or dispositions that enhance the survival of an organism), and that these rules influence the set of cultural entities that are likely to exist. Because these epigenetic rules are themselves shaped by genes Lumsden and Wilson suggest that genes indirectly influence culture. But culture influences genes as well. Different cultural opportunities can lead to shifts in the sorts of epigenetic rules that are useful, and consequently to changes in the successfulness of particular genes in a given population. Lumsden and Wilson (1981) also introduced the concept of culturegens, which are the patterns of culture that are transmitted between individuals (this is closely related to the notion of a meme, see later). They further argue that many culturegens serve to increase the inclusive fitness of those humans who acquire the particular aspects of a culture. Thus, culturegens such as incest taboos (one of Brown’s cultural universals) can aid human genetic fitness by deterring people from mating with their close genetic relatives, thereby avoiding the fitness-reducing consequences of inbreeding (see Chapter 3). Food taboos such as viewing certain animals as unclean and unfit for consumption might have arisen because – in the ancestral environment – such animals were the hosts to a variety of dangerous pathogens (see Chapters 3 and 4). Culturally specific methods for the preparation of food, on the other hand, might have rendered certain foodstuffs safe to eat. In particular, the observation that food from hot parts of the world such as Africa, South Asia and the Mediterranean tends to be highly spiced, whereas food from cold countries such as Scandinavia, Britain and the Polar regions is traditionally more bland, can be at least partly explained by the anti- biotic properties of spices such as garlic, and chili (see Figure 14.3). Food left out in hotter climates becomes infested by potentially life-threatening bacteria and other parasites much more rapidly than it does in cooler regions. But culture also has effects on genetic evolution. You may know that some people are un- able to digest lactose, a sugar found in milk and hence have to avoid milk and its products in their diet. Lactose intolerance, however, is no mystery: milk is a food designed to feed babies and most mammals lose the ability to digest it once they become adults by turning off the gene that produc- es the digestive enzyme lactase. What needs to be explained, therefore, is not lactose intolerance but lactose tolerance. The answer, it seems, is culture. Those people whose ancestors habitually herded cows, sheep or goats have a genetic mutation that supports lactase production in adulthood, those whose ancestors did not, tend to turn off lactase production following weaning (Bloom and Sherman, 2005). Thus, cultural practices can cause selective pressures that, over generations, affect biological evolution. A similar story can be told for alcohol tolerance. Alcohol is a poison unless it is metabolised by the enzyme alcohol dehydrogenase (ADH). ADH, and hence alcohol tolerance, is higher among Europeans than South Asians possibly because alcohol was discovered by Europeans as a way of purifying water (most people in Europe, even children, drank a weak ale) whereas South Asians used antimicrobial herbs in the form of tea for the same purpose (Osier et al., 2002). Thus in Europe people possessing genes for low levels of ADH were less able to avail themselves of the purifying effects of alcohol and were more likely to die and therefore less likely to pass their genes on to the next generation. Some people, it seems, are designed for beer.  Evolutionary Theories of Culture 399 garlic onion allspice oregano thyme cinnamon tarragon cumin cloves lemon grass bay leaf chilli rosemanry marjoram mustard caraway mint sage fennel corriander dill nutmeg basil parsley cardamom pepper ginger aniseed celery seed lemon/lime 0 25 50 75 100 Percentage of bacteria inhibited Figure 14.3 The antimicrobial properties of different spices and herbs. Note that some of the more powerful ones (e.g. garlic, allspice, chilies) tend to be eaten in hot countries. Niche Construction and the Evolution of Culture The examples of lactose and alcohol tolerance used to be considered interesting quirks of the story of the evolution of culture, but it now seems that they may, in many ways, be of central importance to the evolution of human culture (Laland, 2017a). This is a theory of niche construction proposed by evolutionary biologist Kevin Laland and his team at the University of St Andrews in Scotland. Consider the story of the evolution of lactose tolerance, by herding animals humans unwittingly manufactured a selective pressure that changed their genotype by creating a niche, the consumption of milk, that didn’t exist before. It is all too easy to consider the environment as something independ- ent from us that affects us psychologically through learning, and biologically through evolution. But to a large degree humans have created their own environment, and with it unique selective pressures. And it is not just humans that do this: many organisms big and small actively change their environ- ment whether it is beavers building dams, spiders building webs, or chimpanzees using sticks to fish for termites and rocks to crack nuts (see Box 14.2). In most cases, non-humans have a small number 400 Evolutionary Psychology and Culture of such artefacts and practices, humans have many thousands, and each has the potential to change our biology. We have already discussed alcohol and lactose tolerance, but it has been suggested that the cultural practice of cooking placed many selection pressures on humans: softer food reduced the necessity for large teeth and strong jaws and, perhaps most importantly, cooked food meant that food could be eaten and digested much more rapidly freeing up time to do other things, including innovating and learning new cultural practices: culture begets culture (Wrangham, 2009). And this is the point of Laland’s argument, many cognitive phenomena, he suggests, are adaptations to the products of culture itself. In order to explore this further, Laland and colleagues (Rendell et al., 2010) created a computer simulation in which cultural ‘strategies’ would compete for supremacy. This was inspired by Robert Axelrod’s competition which explored the evolution of co- operation (see Chapter 8). The researchers designed a computerised world with various ecological problems to solve and invited interested parties around the world to develop computer-based agents to inhabit this world and solve its various problems. Once submitted, agents would be placed in competition with other agents and the ones that were most successful would go through to another round until a winner was declared. The world was designed so that agents had only three available strategies. Innovate rep- resents asocial learning, working out a solution to a problem on your own. Observe is observing and copying the solutions and strategies of others. Exploit is solving the problem. The tournament is time limited: the more time and effort that you spend on, for example, working out a solution yourself (using innovate), the less time you have to deploy (exploit) that strategy and gain rewards. Points are gained only for problems that are successfully solved. Laland’s team found that the most successful agents copied a lot and, crucially, that they copied efficiently and with great fidelity (those that copied a lot, but did it badly were among the worst performing agents). This led them to hypothesise that maybe what drove human evolution was an increasing ability to copy others efficiently and effectively and for those who are copied to facilitate the process of being copied. As discussed previously, the drive for efficient and high-fidelity copying places a selective pressure on brains to evolve cognitive capabilities such as theory of mind (to work out the actor’s intention) and perception (to better see what you should copy) and as brains become bigger and more complex copying becomes more faithful, faster and more complex which places a pres- sure to refine these cognitive capacities which leads to bigger brains which … We hope you get the picture: bigger brains, mean more complex culture which drives brains to become bigger and the process continues. Technically a process in which more of some- thing produces more of something is called a positive feedback loop and Laland sees this as central to what makes humans different in the complexity of their culture, in the huge size of the brains, in their ubiquity across the globe. For one reason or another (Laland puts the origins down to the craft- ing of stone tools by our ancestors) no other animal has experienced the evolutionary after-burner of positive feedback that has been experienced by our species. This is an intriguing theory because, unlike some others in which the evolution of culture had to wait until our brains had evolved language, theory of mind and a host of other clever tricks, culture itself, and the ability to acquire it, predated these capabilities. Yes, even language. As we discussed in Chapter 10, Laland’s argument is that language evolved as an efficient way for humans to transmit culture: one doesn’t need to merely show someone how to do things, one can tell them how to do it and explain why it is done that way. Not only are humans natural learners, they are also, according to this theory, natural teachers.  Evolutionary Theories of Culture 401 The Future of Culture-Gene Theories All these theories outlined above are still in their infancy as theoretical accounts of the development of the interaction between genes and the environment. Each of them, however, seems promising as a way of explaining the evolution of culture. There are some differences between them. For instance, Tooby and Cosmides and Lumsden and Wilson place more emphasis on the biological basis of spe- cific cultural practices, whereas Richerson and Boyd focus more on transmitted elements of culture. This is, however, largely a difference of emphasis as surely both are important factors in a complete understanding of culture. It seems that the most recent of these theories – that developed by Laland and his colleagues – might unify these theories, focusing as it does on the interaction between genes and the environment and especially in the way in which it suggests that culture drove the expansion of the human brain and thereby cognitive capabilities. Box 14.3 Is Cultural Evolution Always Progressive? Are cultural practices arbitrary, or can they be seen as adaptations to the environment? Some ev- idence that shows how cultural practices adapt to the prevailing environmental conditions can be seen in a natural experiment in Polynesia (see Diamond, 1998). The Maori is a group of people descended from Polynesian farmers who colonised New Zealand around the eleventh century. Not long after (probably by the thirteenth or fourteenth century) a group of Maori – most proba- bly from the West coast of New Zealand’s North Island – colonised a neighbouring island which the new inhabitants named Rekohu some 500 miles to the east (the official name for Rekohu is now the Chatham islands). Initially the two groups would have been culturally similar, but over time their trajectories diverged. By the 1830s the Maori had reached an advanced stage of cultural evolution, engaging in intensive agriculture. This method of exploiting the land meant that they produced food in such abundance that their society could afford to support non-food producing specialists such as crafts- men, bureaucrats, hereditary chiefs who did no manual work and – because many of the societies were continually at war – part-time soldiers. At the same time, the colonists on Rekohu, now known as the Moriori, seemed to have ‘regressed’. Instead of engaging in intensive farming and supporting specialist craftsmen, soldiers and a sophisticated political system, the Moriori had re- verted to being hunter-gatherers with little cultural specialisation and were more peaceable than the warlike Maori who – true to form – invaded in 1835 and took over the island. What had hap- pened? Does this not show that cultural practices are not adaptive? In fact, it shows the opposite. One of the great misconceptions about culture is that there is an inevitable progress towards more complex forms of agriculture, technological innovation, specialisation and social organisation. (There is a similar misconception that biological evolution will always produce organisms that are bigger, faster and stronger.) In many situations, such a trajectory is unsustainable. Rekohu was much colder than North Island New Zealand (the name Rekohu describes the mist that clings to the island); this meant that the seed crops originally taken when the islands were colonised failed. Additionally, Rekohu had an abundance of naturally occurring food such as fish, seals, sea birds, small mammals, seafood and edible vegetation. So in this case it made sense to move from agriculture to hunting and gathering. Because foraging is unable to produce the surplus of food that intensive agriculture produces, the Moriori were unable to support specialist craftsmen, 402 Evolutionary Psychology and Culture Box 14.3 (cont.) so the sophistication of artefacts decreased. They were also unable to fund a governing class so the political organisation became simpler – just a hereditary chief and a small number of aides. Because they were on an island with no other tribes around them, there was no need to fund sol- diers, even if they could have afforded them. Thus the hunter-gatherer lifestyle was actually more adaptive in the case of the Moriori. There were also some innovations. The tribespeople realised that naturally occurring food was abundant only so long as the population didn’t increase beyond a certain point, otherwise the stocks would rapidly deplete, so they engaged in population control by castrating a percentage of their male offspring. As a result of this population management, and other measures, the Moriori managed to preserve their food resources throughout their history. Their seal colonies, for example, were managed by killing only older male seals and remained virtually unchanged in number until Europeans arrived in the late eighteenth century. The Mori- ori are not alone in abandoning ‘progressive’ practices such as agriculture, and in nearly all cases where this has happened it has been due to sound practical reasons. Cultural Information as Replicator: The Meme’s-Eye View Many of the examples of cultural phenomena given above are obviously advantageous. Most would agree that pottery, fire, incest taboos and ways of purifying food and water have a positive effect on fitness, but it is not always so easy to see the fitness-enhancing property of a cultural practice. Clothing is undoubtedly useful, but what about fashion? What are the consequences – in terms of fitness – of whether you wear your baseball cap with the peak up, down or round the back of your head? Some cultural practices seem to have no obvious direct benefit to fitness, inclusive or other- wise. This observation leads to a radical hypothesis: maybe some cultural behaviour is not for our benefit at all; maybe it is just for its own benefit. In The Selfish Gene (1976) Richard Dawkins argues that to understand genes fully, we need to adopt the ‘gene’s eye view’ (see Chapter 2). Successful genes (ones that are prevalent in the gene pool) need not be beneficial to the individual organism in which they reside, all that matters is that any lack of beneficence does not harm, or increases their chances of being passed on to the next generation. We often think that genes are there for the benefit of the individual in which they reside, but this is not always the case as there is only one player who always benefits: the gene itself (again see Chapter 2). As examples you might consider the self-sacrificial behaviour of the male redback widow spider who offers himself to his partner as a post-copulatory snack, bees that kill themselves in defence of their hive, or, closer to home, consider your own body. While there are clearly parts of your body that enable your survival and general well-being, your heart, for example, or your hands, there are other parts that do not. Your sexual organs really have nothing to do with you as an individual: they are merely convenient escape routes to enable genes, packaged into sperm or ova, to escape your body and found the next generation. These behaviours evolved not because they benefit- ed the individual, but because they benefited the genes for that behaviour. Likewise, many cultural phenomena such as music and chastity might have no benefit to the individual, all that matters is that they replicate. Like viruses, units or conglomerations of units of cultural inheritance spread by capitalising on the nature of the human mind. Dawkins labelled these units of cultural inheritance memes by analogy to genes, the units of biological inheritance.  Cultural Information as Replicator: The Meme’s-Eye View 403 What Are Memes? The definition of a meme varies depending on the particular author that one consults; this is not necessarily a great problem; memetics (the study of memes) is a relatively young discipline and it is therefore unsurprising that people think of memes in different ways. Dawkins (1982) proposes that a meme is ‘a unit of cultural inheritance … naturally selected by virtue of its ‘phenotypic’ conse- quences on its own survival and replication’ (109). Dawkins (1976) gives examples of memes: they are ‘tunes, catch-phrases, clothes fashions, ways of making pots or building arches’ (206). Impor- tantly, according to Dawkins, the meme is not the tune, the catchphrase or the arch; these are merely the physical manifestations of the meme. The meme is the idea of the arch, or more formally the underlying mental representation of ‘archness’. In explaining memes, Dawkins makes a distinction analogous to that between genotype and phenotype. The colour of a human iris, for example, is the phenotypic expression of the underlying genotype. Likewise, an arch is the phenotypic expression of the underlying meme for an arch. A similar distinction was made by Cloak (1975) who distin- guished between m-culture (culture that is ‘out there’ in the real world) and i-culture (culture that exists in people’s heads). We must be careful of applying distinctions such as that of genotype and phenotype too closely to memes – we can find that it soon starts to become confusing. If the idea of an arch is a meme, then how would you classify a set of instructions on how to build an arch? Is that also a meme? If you wrote down the music for Yankee Doodle, would that be a meme? Susan Blackmore (1999; 2010) proposes that the written form also constitutes a meme but sensibly cautions that one should not expect to use the language of genes to apply to memes too closely. After all, memes are not genes: they are a different kind of replicator and therefore obey their own rules. Another ex- ample of this is in deciding what a meme is. Critics (e.g. Wimsatt, 1999) have questioned how one identifies an individual meme. In certain cases, such as a joke or a short tune, the meme is easily identified, but in other cases such as a religion is the religion itself a meme or is it many memes, and if the latter, where are the boundaries between individual memes? The problem with this criticism is that exactly the same criticism could be levelled at genes (Haig, 2006). The generally accepted way of defining a gene (and the one we discussed in Chapter 2) is as a unit of DNA that codes for a polypeptide or RNA string, but there are other ways of defining them. In the Selfish Gene Dawkins (1976) uses George C. Williams’ (1966) definition of a gene as ‘any portion of chromosomal mate- rial that potentially lasts for enough generations to serve as a unit of natural selection’ (28). While this might seem a vague definition, from the point of view of selection it is the definition that matters. Genes are not selected directly but are selected by virtue of the effect that they have on the phenotype (they cause us to be lactose tolerant, or to have colour vision); they are not selected because they code for this polypeptide or that RNA sequence. So the definition of a gene depends upon what is useful: if we are biochemists, then the first one is more useful; if we are evolutionary psychologists, behavioural ecologists or evolutionary biologists, then the latter is more useful. If we are interested in the behavioural consequences of memes, then we can follow Dawkins’ definition of a gene and simply define it as ‘that which is copied’. Notwithstanding this debate, we can see that a meme does have a physical basis, although it is unlikely that it is as simple as the way that genes are manifested in DNA (and that is hardly trivial). Maybe, when brain scanning technologies have developed beyond those currently available, we might be able to see how particular ideas are manifested in the brain, we might even be able to tell whether or not a person has the meme for arch. But we need not wait until then to study memes. Recall from Chapters 1 and 2 that Gregor Mendel never saw a gene – he inferred their existence and 404 Evolutionary Psychology and Culture nature from observing the results of his experiments on pea plants which allowed him to formulate his laws of genetics. Likewise, it is possible to study the nature and transmission of memes without detailed knowledge of their physical basis, so despite the critics the difference between memes and genes is not as great as it might at first seem. Box 14.4 Myths, Mind Viruses and the Internet One curious type of cultural entity that spreads from person to person is the urban myth. These take the form of true stories but are often expressed as happening to a person only distantly known to the teller: usually ‘a friend of a friend’. The stories are often funny (the friend of a friend who came downstairs naked to be greeted by his friends and family who had organised a surprise party in his house), and sometimes contain warnings (sewer-living alligators in the United States, rats found in hamburgers, aliens masquerading as family members). From a rep- licator’s point of view, urban myths are tailor-made to infect human minds. Human beings like telling stories, particularly if they invoke emotional reactions in their audience such as mirth, shock or incredulity. The advent of the Internet drastically increased the ability of these ‘mind vi- ruses’ (Dawkins, 1995) to replicate. Now we don’t even need to remember the joke, story or idea, in order to transmit it to our friends and acquaintances. The ready availability of internet access, coupled with the ease with which individuals can copy or forward messages, greatly facilitates the proliferation of cultural information. In the 1980s and early 1990s, for example, millions of email users received the following message: A little boy (his name varies), dying of an incurable disease (the disease varies), wants to make it in the Guinness Book of Records for ‘the most get-well cards’. Well-meaning computer users ask you to send a card so the little boy gets his dying wish. The boy was eventually identified as Craig Shergold and as a result of the media coverage he came to the attention of American billionaire John Kluge who arranged for Craig to undergo a new form of treatment at the University of Virginia Medical Center in 1991. The operation was a success but still the cards kept coming, forcing the family to move to a new home which was given its own postal code. By 2007 it was estimated that he had received around 350 million cards. He requested that people stop. Perhaps even more pernicious are emails that warn of bogus computer viruses. When told that they may have a virus, most people’s response is to panic. As we were writing the first edition of this book in 2001, one of us received the following message from a close friend via email. PLEASE MAKE SURE YOU FOLLOW THE INSTRUCTIONS THAT FOLLOW AS THE VIRUS IS SPREAD THROUGH AN ADDRESS BOOK AND, THEREFORE, WILL NOW BE IN YOURS! THE VIRUS LIES DORMANT FOR 14 DAYS, THEN KILLS YOUR HARD DRIVE. PLEASE FORWARD THESE DIRECTIONS ON HOW TO REMOVE IT TO EVERY- ONE IN YOUR ADDRESS BOOK The message then contained detailed instructions on how to delete the offending file, called ‘sulf- nbk.exe’, which was in fact a legitimate part of the Windows operating system and removing it stopped the computer from working properly.  Cultural Information as Replicator: The Meme’s-Eye View 405 Box 14.4 (cont.) Nowadays the internet is full of memes and the word has entered everyday usage to de- scribe images, videos, catchphrases and misinformation that are spread by people coming across something funny, interesting or shocking and sharing it with their friends. Sometimes memes get you to do something more than copy. In 2014 the Ice Bucket Challenge became a cultural phenomenon (see Figure 14.4). Designed to raise money for a motor neurone disease charity it required people to pour a bucket of cold water over their heads while being filmed. The video was then uploaded to social media, and the participant then nominated another person (usually a friend) who then had 24 hours to do likewise. Eventually 2.4 million videos were created and $220 million was raised for the charity. Such a powerful phenomenon hasn’t escaped the attention of marketers and viral market- ing promotes products by creating funny, interesting or shocking memes which are copied and shared via online social networks. Figure 14.4 Formula 1 driver Daniel Ricciardo participates in the Ice Bucket Challenge in 2014. How Useful Is Memetics? There is something attractive about the idea of memes, something that has made the idea spread, infect the minds of renowned philosophers, scientists and the public alike. The meme meme has been greatly aided by the fact that many of its advocates are wonderful wordsmiths and storytellers (prin- cipally Dawkins and Dennett). Many of the critics of memetics have pointed to various disanalogies between genes and memes (Midgley, 2000; Wimsatt, 1999): for example, the difficulties in isolating individual memes and differences in mutations discussed above. However, the biggest problem with memetics is probably less conceptual and more functional: what can you actually do with it? Adopting the gene-centred view of evolution (see Chapter 2) was genuinely revolutionary in biology, enabling 406 Evolutionary Psychology and Culture us to explain behaviours that were previously mysterious such as altruism among kin, self-sacrificial behaviour, sibling rivalry and parent–offspring conflict to name but a few (see Chapter 7); while the meme-centred view of cultural evolution is doubtless fascinating, it has failed to explain any phenom- ena that aren’t explainable by traditional concepts such as conformity, obedience, compliance and memorability (Haney et al., 1973; Milgram, 1963; Asch, 1956; Centola et al., 2005; Bartlett, 1932). Other Forms of Cultural Learning Humans do not only have an imperative to acquire culture, they are also disposed to transmit cul- ture through teaching and other means. Language obviously plays an important role in this form of cultural transmission and, as we discussed above, Kevin Laland believes that the need for efficient teaching is what led to the evolution of language. Unlike other animals, humans can describe to their children what the best tasting fruits look like, how to prepare food properly, or how to turn animal skins into clothing. According to Tomasello et al. (1993) this instructed learning is of particular importance for children because instructions are internalised and used to regulate their subsequent cognitions and actions. Not only do young children acquire specific skills through instruction, they also learn more general skills such as self-monitoring. Learning by instruction greatly extends the range of things that we are able to learn. As we have seen, it is possible for an animal such as a Macaque to learn how to wash potatoes by imitating others, but this requires them to see the value in potato washing. With language we don’t have to leave this to chance, we can explain the value of an activity, thereby vastly improving the process of transmission. We can say ‘I’m cooking this food to stop it from causing illness’, ‘I’m praying to save my spirit from damnation’, or ‘Don’t eat the fruit of that tree because it will make you ill’. Language not only facilitates the spread of culture, it greatly increases the sorts of cultural entities that can be spread. Why Is There Such a Difference in Cultural Wealth? Why do different areas of the world have such differences in wealth and technology? Why, for in- stance, is Europe rich and sub-Saharan Africa poor? Why was it Europe that colonised the Americas rather than the other way round? Answers to this question are various. Some have suggested that Europeans – especially Northern Europeans – are biologically superior: that they are innately more intelligent or more suited to leadership. It perhaps goes without saying that there is no evidence for such explanations. Others have pointed out that the reason Europe (or more correctly Eurasia – the landmass that incorporates Europe and Asia) dominated the other continents of the world (North and South America, Australia and Africa) was due to Europeans’ discovery and use of steel weapons, their success at domesticating animals (including horses) and their sophisticated political organisation. While there is truth in this assertion, biologist Jared Diamond (1997) felt such an explanation incomplete as it begs further questions as to why the Eurasians were the ones with the steel weapons, the domesticated animals and the political organisation. In short, he sought ultimate explanations for the way things are, not simply proximate explanations. Figure 14.5 shows a schematic of Diamond’s framework. At the bottom of the diagram are the proximate causes of the Eurasian domination of recent history: domesticated animals such as horses for pulling ploughs and using in war, technologies that enable travel and efficient killing, the organisational capacities to manage colonies and large armies, and finally, epidemic diseases. This last category often surprises people; how did epidemic diseases enable Eurasians to colonise the rest  Why Is There Such a Difference in Cultural Wealth? 407 of the world? During many sorties abroad, Eurasian soldiers often found they didn’t need to engage with the natives; the diseases that the soldiers carried with them did their work for them. For exam- ple, the Spanish colonisation of South America was made much easier because the population had been decimated by smallpox brought over from Europe. But why did the Spaniards have smallpox rather than the South Americans? It turns out that most epidemic diseases are the product of agri- culture. The main killers of the past few hundred years – smallpox, influenza, cholera, tuberculosis, bubonic plague, malaria and measles – all derived from animals, often domesticated animals. South Americans having few if any domesticated animals simply did not have the opportunity to benefit from this early (and unintentional) form of biological warfare. ULTIMATE East/west axis FACTORS Many suitable wild Ease of species species spreading Many domesticated plant and animal species Food surpluses, food storage Large, dense, sedentary, stratified societies Technology PROXIMATE guns, steel Ocean-going political epidemic horses FACTORS swords ships organisations diseases Figure 14.5 A schematic of the causal factors (proximate and ultimate) that led to the development of advanced civilisation. 408 Evolutionary Psychology and Culture Ultimately, Diamond suggests, Eurasians were at an advantage because the continent ex- tends a vast distance in an east–west direction whereas the other continents do not. This east–west axis means that animals and plants domesticated in one part of Eurasia can be imported to another part with relative ease – something which is not true where the axis is primarily north–south as it is in Africa and South America. Moving north or south will lead to significant changes in climate – something that is potentially harmful for the crops or livestock. Eurasia also had the largest number of animals suitable for domestication. In fact, of the 14 large domesticated animals, Eurasia had 13, South America 1 (the ancestor of the llama) and Australia, North America and sub-Saharan Africa none at all. Domestication of plants and animals made agriculture possible and the resultant food sur- plus meant that many more mouths could be fed than by hunting and gathering. The explosion in population had two consequences. First it meant that there was a need for some form of centralised political organisation, and second it meant that the people in these societies could specialise, which led to the development of the aforementioned technologies. So where did civilisation begin? The evidence suggests it began in a region known as the Fertile Crescent which spans the area that now includes Syria, Lebanon and Iraq. This area appears to be the birthplace not just of agriculture but also the alphabet and is the area which was the birth- place of the Indo-European language family (see Chapter 10) that now includes most European languages (e.g. English, Italian, Norwegian and Russian), the languages of the Indian sub-continent (e.g. Hindi, Urdu, Punjabi) and some Middle Eastern Languages (e.g. Persian and Pashto). Diamond’s theory shows that the unequal distribution of wealth is largely the result of historical accident, Eurasians had the raw materials of civilisation, whereas those living on other continents did not. The Importance of Specialisation in Culture One of the benefits of moving to agriculture is that it enabled cultural specialisation. Matt Ridley (2010) gives the following example. Imagine that there are two people Adam and Oz. Adam takes four hours to make a spear and three hours to make an axe (total time seven hours). Oz, on the other hand, takes one hour to make a spear and two hours to make an axe (total time three hours). Oz is better at both spears and axes so does Oz need Adam? Superficially you might think that the answer is no, Oz is more efficient at making both spears and axes than Adam so why would he need his help? In fact if Oz specialised in making spears he could make two spears in two hours (a saving of one hour if he made both spears and axes), and if Adam specialised in making axes he could make two axes in six hours (again with a saving of one hour). And of course, now that Oz is focused solely on spears and Adam on axes the extra practice will make them even more efficient than if they were generalists. The moral is that it is always better to offload a task that you are not so good at even if the person to whom you offload it is even less efficient than you are. Of course a person only needs so many spears or axes so this system only works where there is a system of trade either by a system of favours – Oz gives Adam a spear when Adam needs a spear, Adam gives Oz an axe when Oz needs an axe – some kind of barter system – one spear is worth two axes – or some kind of token economy, such as money. The biologist Mark Pagel (2012) argues that the evolution of language was an essential component in enabling trade to happen. Chimpanzee culture, he argues, is restricted by their inability to do the deals nec- essary for specialisation to occur. Likewise, it seems that although Neanderthals had sophisticated cultural artefacts there is little evidence that they traded. Neanderthal artefacts were always made  The Importance of Culture in the Development of Culture 409 of local materials whereas the artefacts of contemporary ancestral humans were often made from non-local materials, suggesting that these were obtained through trade (Gamble, 1999). Research by Horan et al. (2005) suggests that the reason why Neanderthals became extinct is because they were outcompeted by our ancestors who were able to develop better technologies as a result of trade. There are many consequences of trade. First, goods and services become cheaper and there- fore more plentiful so that everyone, not just the privileged few, can afford a spear, clothes or protec- tion by way of a professional army. As an example of this Ridley cites the work of economist William D. Nordhaus (1996) who attempts to estimate how many hours the average person would have to work to purchase 1000 lumens of light for a single hour (lumens are the SI unit of how much visible light is emitted by source, 1000 lumens is about the brightness of an average household light bulb). In 1992 the average person would have had to work for half a second to obtain an hour’s worth of light; in 1960 about 3.5 seconds; in 1940, 20 seconds; in 1900, about 15 minutes and in 1800, when candles were used, between 5 and 12 hours, depending on the quality of the candle. The high price of candles in 1800 meant that they were unavailable to most and, when it went dark, people either sat by the fire or went to bed (see Ekirch, 2006, for a fascinating history of life before the electric light). Second, increasing specialisation leads to innovation as experts find increasingly better ways of working with materials or providing services such as cooking or medicine. A final conse- quence is that we are no longer self-sufficient. Given enough time and suitable materials most of us – just like our ancestors – could manufacture a crude hand axe, but how many of us could make something as apparently simple as a pencil? In 1958 economist Leonard Read transcribed the biog- raphy of a pencil: I have a profound lesson to teach. And I can teach this lesson better than can an automo- bile or an airplane or a mechanical dishwasher because – well, because I am seemingly so simple. Simple? Yet, not a single person on the face of this earth knows how to make me. The pencil’s point (as told to Leonard) is that its construction required the efforts of thousands if not millions of people: graphite miners, foresters, lumberjacks, paint manufacturers and so on and not one person has the expertise to acquire, process and assemble the materials to produce the final prod- uct. Lack of self-sufficiency is the price we pay for advanced culture. And before you consider that to be a bad thing Robert Wright (2001; 2007) makes the point that one of the many reasons he doesn’t want to declare war on Japan is the fact that they made his car. His joke is intended to point out that specialisation has reached such a point that we are increasingly dependent on each other and that this is one of the factors that is leading to increased peace throughout the world (see Pinker, 2011). The Importance of Culture in the Development of Culture Imitation, instruction and powerful minds are essential to the development of culture, but there is another factor: culture itself. Agriculture means that not everyone has to be involved in food pro- duction (as we saw with the Maori). Freeing up people leads to a division of labour so that some can work on other things, perhaps developing better farming tools or techniques. Moreover, this benefits farmers who are able to produce more food per hectare, which frees up even more people. Other technologies such as development of writing also had a profound effect on the devel- opment of culture. The earliest known form of writing is Sumerian cuneiform from Mesopotamia dating from before 3000 BC. Later writing systems developed independently, in Mexico before 600 BC and possibly in Ancient Egypt and China, but all other types of writing appear to derive from 410 Evolutionary Psychology and Culture these four (or two) sources. Writing enables us to share expertise with people we have never met; it also enables us to learn from people who died many years ago. Writing also means that cultural en- tities can be copied with far greater fidelity than if they were passed along only by the spoken word, and ultimately enables the development of mathematics and science. More recently developments in communications technology from the printing press to the Internet have had profound effects on the way that we live our lives. The Importance of Horizontal Transmission As we have seen, the transmission of genetic information is always vertically downwards, in that children inherit their genes from their parents. Cultural transmission, on the other hand, can occur in any direction. The most frequently discussed form of transmission is that which is passed vertically downward, as happens when a human child (or perhaps chimp) learns from an adult. It can, however, also be transmitted vertically upwards, such as when a parent assumes an interest first adopted by his children, and it can be transmitted in a horizontal fashion such as when people trade ideas as dis- cussed above. Interestingly, while a great deal of research has focused on the transmission of culture from parent to offspring, rather less effort has been placed on the horizontal forms of transmission, especially those that occur in childhood. This is curious, since it could be argued that horizontal transmission is of paramount importance if culture is to evolve (Harris, 1998; see Chapter 6). The physicist Max Planck suggested that new theories triumph over old not because adher- ents of the old theory embrace the new one, but rather because the adherents of the old theory die out and are replaced by open-minded younger scientists. Whether or not this is universally true (see Hull, 2000), there is certainly some truth in the notion that the great cultural and scientific innova- tors tend to be young rather than old. Historical examples are manifest. For example Einstein was 28 when he published his theory of general relativity, and Darwin was 29 when he formulated the idea of evolution by natural selection. A study conducted by Lehman (1953) looked at the ages at which individuals from a variety of disciplines did their best work (see Table 14.1). This research suggests that for most disciplines the peak age is between the late twenties and mid thirties (see Over, 1988, for a critique of this work). More mundanely, it is the young who most readily adopt new technology (itself usually produced by younger rather than older people) and practices. The first macaque to wash sweet po- Table 14.1 The peak ages at which individuals from a variety of disciplines were at their most productive Discipline Peak age in years Astronomers 24–9 Poets 25–35 Chemists 30–4 Writers of great books 30–4 Philosophers 35–9 Psychologists 35–9 Writers of best sellers 40–4 Metaphysicians 40–9 Mean 32.5–37.9 Peak age 35 Source: Lehman (1953).  The Importance of Culture in the Development of Culture 411 tatoes in the Koshima island group was a juvenile (see Box 14.2) and the younger macaques took up this innovation more readily than the older members of the group. The young are therefore the engines of cultural evolution. The psychologist Judith Harris’ proposed that children are more influenced by their peer group than by the parents. This so-called group socialisation theory (Harris, 1998) proposed that – in stark contrast to the prevailing vertically down notion of cultural transmission – the peer-to-peer horizontal form of transmission might be more important in the enculturation of individuals. We may now be able to see a reason why group socialisation might be an evolutionarily sensible strate- gy. Societies that faithfully transmit ideas vertically downwards would tend to be rather static; they would be able to say how this thing or that thing had been done in exactly the same way for thou- sands of years, and they would be right. If this culture lived in a vacuum this would be fine, but we live in an uncertain world that often changes rapidly. The history of humanity is one of competition; humans compete not only with the physical environment, but also with other people in different groups. In such a situation, it would pay a society to adapt quickly to develop new means of keeping themselves warm, new ways of hunting or farming food, to develop new weapons and battle tactics. For this to happen, we need not only innovators (who, as we have argued will tend to be young) but also a group of willing disciples ready to take up and employ the new ideas. Thus, the desire of the young to learn from each other might be an essential component in rapid cultural evolution. Striking a Balance between Horizontal and Vertical Transmission Would it not make evolutionary sense for older people to adopt new ideas with the enthusiasm of the young? Perhaps it would, but there may be barriers to this happening. Perhaps it is just a side effect of the way that the mind works that older people find it difficult to take on new ideas (as stated in the famous proverb that you can’t teach an old dog new tricks). Once a person has acquired a particular way of doing things it might be difficult to learn new ones. But these are proximate explanations; is there any reason why the brain might not have evolved to make new ideas easier to adopt? Maybe the correct mutations have simply not arisen to enable older people rapidly to adopt new ideas, or maybe they did arise but had unfortunate costs that rendered them unsustainable. There may also be a way in which it might be adaptive for older people to be comparatively unreceptive to new ideas and practices. As well as it being disadvantageous for culture to evolve too slowly, it can also be damaging for it to evolve too quickly. Imagine what it would be like to have innovations proposed and taken up apace without any real consideration as to how beneficial such ideas might actually be. Such a society could end up destroying itself as rival camps battle for their own favourite way of doing things, or being destroyed by their adopting an unworkable practice. Perhaps older people act as brakes on cultural evolution; by being scornful of the new, they might ensure that new ideas generated and championed by the young are properly tested out before they are applied, with potentially disastrous consequences. Box 14.5 Evolution and Religion Religion is a cultural universal, which is to say that religious belief exists in all cultures. Given that religion often leads people to behave in apparently un-Darwinian ways, it warrants explana- tion. For example religious people will sometimes take vows of celibacy, will sacrifice themselves 412 Evolutionary Psychology and Culture Box 14.5 (cont.) or will give up a substantial portion of their resources for their religion – all behaviours which hardly seem designed to maximise inclusive fitness. Is religion, therefore maladaptive? Or might there be some adaptive explanation for religion? David Sloan Wilson (2002) suggests that we can consider religion as a kind of superorganism which promotes the survival and reproduction of the group rather than the individual members of the group. Thus the fact that some people might reduce their fitness through self-sacrifice is irrelevant, what matters is that the group as a whole benefits. Successful religions (ones that have many adherents) are those where the group as a whole performs better than groups which have different religions, or no religions at all. What matters, therefore is the reproductive fitness of the religion itself which is linked to, but not dependent upon, the fitness of the individual adherents to that religion. Wilson’s theory therefore invokes group rather than gene (or individual) selection to explain religion, although unlike early group selectionists (see Chapter 2) Wilson doesn’t rule out the existence of individual selection. An alternative is provided by anthropologist Scott Atran (2002), who attempts to explain religion using more conventional processes operating at the level of the individual. According to Atran, religion is not an adaptation, rather it emerges as a by-product (or ‘spandrel’; see Chapter 1) of other processes which are adaptive. The first is people’s predisposition to perceive agency. For example, in a famous study by Fritz Heider and Mary-Ann Simmel participants were shown a film depicting two triangles and a circle moving in and out of a box. When asked to describe what was happening participants attributed agency and mental states to the shapes. For example, the larger triangle was described as an aggressor. The second of Atran’s processes is causal attri- bution. When two events happen close together in time and space people often assume that one is causing the other even if no mechanism can be seen linking the two events. This can give rise to superstitious behaviour. For instance, if a person happens to be wearing a particular item of clothing when their favourite team wins, they might continue to wear it on subsequent occasions in the hope that it will bring them luck. A third process is theory of mind. As we saw in Chapter 5 we attribute mental states not just to genuine intentional agents, but to all manner of things including inanimate objects such as cars, and computers. These three mechanisms play a role in helping us to predict and understand the world, but – as the above examples demonstrate – can be misapplied so that we see agency, causality and intentionality where there is none. This can, according to Atran, lead to the perception that there are intelligent agents (gods) who can inter- vene in the world. A number of other theories have been proposed to explain religion. In his famous (some would say notorious) work The God Delusion (2006), Richard Dawkins argues that a different mechanism might underlie the transmission of religious beliefs. He argues that children need to acquire skills and knowledge from adults in order to negotiate the world; children’s blind accept- ance of cultural mores can be seen as part of an adaptive ‘culture acquisition device’. This makes them susceptible to all kinds of information, including acquisition of religious information. Re- ligion can therefore be thought of as a kind of meme (or system of memes – a memeplex; see Blackmore, 1999) that children acquire uncritically. From this perspective, religion needn’t be beneficial to the individual, all that matters is the ‘fitness’ of the meme – religion itself. A similar line is taken up by Daniel Dennett in his book Breaking the Spell (2006).  Summary 413 Finally, we should sound a warning about the interpretation of the benefits of culture. It is all too easy to think of culture as benefiting a society or being for ‘the good of the group’. In strict evolutionary terms this is not the case. As we saw in Chapter 2, there is little evidence that selection occurs at the level of the group. Instead most modern evolutionists adopt a ‘gene-centred’ perspec- tive in which the benefits of culture somehow increase inclusive fitness of the members of that group (or rather the genes of its members). Conclusions Many consider culture to be something that has nothing to do with biology and evolution; this is likely to be wrong on two counts. First, some cultural practices (e.g. incest taboos) might in some way have a genetic basis (Lumsden and Wilson, 1981). Brown’s accounts of cultural universals have been used as evidence that this might be the case. Second, it appears that the fact that we have cul- ture at all might be down to evolution. If Boyd and Richerson are correct, culture evolved as a sec- ond mode of inheritance as a way of enabling human beings to deal with a changing environment. Certainly, it seems that from a young age human engage in a process of enculturation, and that the cognitive capacities necessary for acquiring complex culture seem to be uniquely human. Kevin La- land steps into this arena and forcefully argues that culture isn’t something that ‘just happens’ when we have big brains that evolved for some other reason. On the contrary the very fact that we have big brains is a product of culture which is itself the result of our having (slightly less) big brains. Understanding culture surely represents one of the most difficult tasks for evolutionists, and we hope we have shown that the attempts so far raise more questions than it answers. To what extent are cultural universals the result of human nature? What headway might be made in the exploration of contingent universals? Why did culture evolve? Is it meaningful to treat cultural in- formation as a selfish replicator? What specific psychological mechanisms are required for cultural transmission and so on? Perhaps more than any other area addressed in this book, the application of evolutionary theory to the understanding of culture reveals how adopting a Darwinian framework can not only help answer existing questions but can unearth new and interesting questions to set a research agenda for the twenty-first century. We’ve come a long way culturally in 10,000 years but evolutionary psychologists would argue that if we are to understand the human mind then we would do well to realise that that mind is the same one that scanned the plains of equatorial Africa in the days of our Pleistocene ancestors. Summary Early theories of culture (described by adherents to the Santa Barbara School as adopting the Standard Social Sciences Model or SSSM, otherwise known as cultural relativism) tended to reject the importance of biology in explaining cultural phenomena. Instead, culture was seen as a superorganism unaffected by human nature. In contrast to the view of the cultural relativists, Donald Brown argues that there are many cultural universals, and some of these might be the product of a comparatively fixed underlying human nature. Tooby and Cosmides propose that evoked culture might give rise to contingent universals, practices that are the result of mental models being sensitive to certain environmental conditions. 414 Evolutionary Psychology and Culture Many evolutionists such as Lumsden and Wilson and Tooby and Cosmides argue that many cul- tural practices are constrained by genes; culture exists to improve our inclusive fitness. Richerson and Boyd are more concerned with how our ability to acquire and learn culture evolved, what factors led to the ‘cultural revolution’. They argue that culture provides us with a second mode of inheritance that evolved as a way of adapting to an environment that changed faster than could be addressed by biological evolution. Kevin Laland proposes that once culture got off the ground, it provided a selection pressure for more efficient copying, which drove the expansion of the human brain, and this created more cultural practices. Thus, we have a positive feedback loop which ultimately resulted in humans dominating the world. Memetics is the treatment of information as replicator (memes), it suggests that in many situ- ations, cultural practices and behaviours need not have any benefit to the host. Rather, cultural information is seen as a selfish replicator or mind virus that takes advantage of human beings’ ability to imitate and copy each other. Although many animals appear to change their behaviour by imitating others, none appear to do it quite as much or as efficiently as humans. This has led some researchers to suggest that the ability to imitate might represent an adaptation that enables us to acquire culture (as in Boyd and Richerson’s theory). Specialisation (probably facilitated by the development of agriculture) and trade have led to the incredible advancement of human culture over the cultures of non-human animals which are trans- mitted vertically. Although we typically think of cultural information as being passed on vertically (like biological information), there is reason to believe that a lot of information is passed horizontally between peers; this might be particularly important in childhood. Questions 1. Make a list of examples of cultural practices from around the world (it might be easier to consider some from your own culture first). Consider to what extent each of these practices might be (1) adaptive, (2) maladaptive or (3) neutral with regard to inclusive fitness. To what extent might the theories discussed above (innate, cultural learning, memetic, gene–culture co-evolution) account for the existence of these practices? Are there any that no theory can account for? 2. Technology has a role to play in cultural practices, and modern technologies such as mobile phones, computer games, television and the internet have changed the way we do things to some extent. But have they changed our practices fundamentally? Or do we simply do the same kinds of things we did before, but in a different way? How does this relate to the notion of an evolved human nature? 3. Being self-sufficient is often portrayed as a good thing, both at the individual level and at the na- tional level. To what extent might a lack of self-sufficiency lead to interdependence among people and nations and therefore to greater cooperation and peace? 4. To what extent does culture exist in non-human animals? In what ways do the proposed cultures of such animals differ from human culture?  Further Reading 415 Further Reading Brown, D. E. (1991). Human Universals. New York: McGraw-Hill. Landmark book that describes universals of human culture. Diamond, J. (1998). Guns, Germs and Steel: A Short History of Everybody for the Last 13,000 Years. London: Vintage. A wonderfully scholarly work that tries to provide ultimate explanations for why the world is as it is today. Laland, K. N. (2017). Darwin’s Unfinished Symphony. Princeton, NJ: Princeton University Press. A fascinating book that argues that culture is the driving force of human evolution. Pagel, M. (2012). Wired for Culture: Origins of the Human Social Mind. London: W. W. Norton. Readable account of the origins of culture and sociality and the importance of language in its evolution. Richerson, P. and Boyd, R. (2005). Not by Genes Alone. Chicago: University of Chicago Press. Introduces their notion of dual inheritance theory and the ‘multileveled’ selection of cultural units. Tomasello, M. (1999). The Cultural Origins of Human Cognition. Cambridge, MA: Harvard University Press. Quite a technical book that attempts to explain the many differences between humans and non-humans in terms of cognition and culture.