PSYC20008 Individual and Social Cognition Lecture Notes PDF

PSYC20008 Individual and Social Cognition Justin Park Lecture 1 Evolutionary Social Psychology Justin’s module (see Blackboard for details regarding the entire unit) Weeks 1-4: Lecture on Monday 11:00-13:00 There are essential and recommended readings associated with each lecture Weeks 1-6:...

PSYC20008 Individual and Social Cognition Justin Park Lecture 1 Evolutionary Social Psychology Justin’s module (see Blackboard for details regarding the entire unit) Weeks 1-4: Lecture on Monday 11:00-13:00 There are essential and recommended readings associated with each lecture Weeks 1-6: Drop-in office hour on Monday 14:00-15:00, in person (3D18) and on Zoom You can also post questions on the Blackboard Forum Justin’s lectures (1) Evolutionary Social Psychology (2) Perception of Kin (3) Perception of Other People (4) Stereotyping and Being Stereotyped My topics will consider how we perceive, make sense of, and respond to other humans → social perception and social cognition These capacities include basic perceptual, cognitive, and emotional processes We perceive others individually and as members of social categories, with distinct consequences Broad theoretical background – evolutionary approach Darwin’s theory of evolution by natural selection This theory explains the emergence of new traits (and species) ▪ Organisms vary in their traits (anatomy, physiology) ▪ Some of that variation is inherited, via genes ▪ Some traits are more conducive to survival and reproduction → These traits become more prevalent over generations Evolution of adaptive traits Over time, natural selection produces traits that promote survival and reproduction These traits are called adaptations, and they include physical and behavioural characteristics Biological characteristics that appear ‘designed’ – including animal behaviour – are best explained as evolved adaptations What about learning and the effects of the environment? These must also be explained in terms of evolution – species are predisposed to certain developmental outcomes An example of a behavioural adaptation Fixed action pattern – behavioural sequence that, once triggered, runs to completion Egg retrieval See https://www.youtube.com/watch?v=7PcteKRA3zs Are there behavioural adaptations in humans? If so, what is the nature of the psychological processes underlying those behavioural adaptations? Although biology was transformed by Darwin’s ideas, much of psychology resisted evolutionary theory for a long time For much of the 20th century, common explanations of human behaviour invoked learning – We do what we’ve learned to do (from parents) culture/context – We conform to societal norms rationality – We make plans and carry them out These are valid approaches, but they leave some gaps Evolutionary psychology In the 1970-80s, psychologists started to take seriously the possibility that human behaviour (and corresponding psychological processes) comprise evolved adaptations When this theoretical perspective is applied to social psychological topics, this is referred to as evolutionary social psychology Attachment, mindreading, mate preferences, group relations, etc. The Social Animal Humans evolved in the context of group living (being part of a group was essential) Sociality came with benefits but also introduced problems ▪ exploitation, threat to safety, disease transmission There would have been evolution of specific psychological adaptations that maximise the benefits and minimise the costs associated with group living Implications of evolutionary psychology The ‘mind’ is a collection of functionally specialised (domain-specific) mechanisms, which have been shaped by natural selection over generations, because they solved recurrent problems Each mechanism takes as input information that would have been reliably available and produces output that generates adaptive behaviour e.g. perception of egg-like object → protective behaviour perception of predator → escape behaviour Debate and controversy surrounding evolutionary psychology Can mental capacities be understood as evolved adaptations? What is the role of the environment in shaping what appear to be evolved adaptations? Does this approach imply that we have no control over our behaviour (and thus negative behaviours are justifiable)? Example of an evolutionary approach Pregnancy sickness – why does it exist? One type of explanation focuses on physiological and environmental causes → heightened sensitivity to certain odours and tastes (as a result of hormonal shifts) → those stimuli trigger nausea This explanation focuses on mechanisms (and is known as a proximate explanation) But we can ask a further question: Why is pregnancy accompanied by heightened sensitivity to certain odours/tastes and hormonal shifts? This why question looks for a possible function Is it possible that pregnancy sickness is useful in some way? Profet (1992) argued that pregnancy sickness serves the function of protecting the embryo ▪ Certain foods contain toxins that, while not harmful to adults, may cause birth defects or induce abortions ▪ Pregnancy sickness is strongest in the early part of pregnancy, when the embryo is forming its major organ systems and especially susceptible to toxins ▪ Those with pregnancy sickness don’t avoid all foods but tend to avoid foods that contain high levels of toxins & pathogens (e.g. meat) ▪ Those who experience more severe sickness end up ingesting lower levels of toxins – consequently, they are less likely to have miscarriages or infants with birth defects Profet’s account highlights the function and evolutionary origins of pregnancy sickness (and is known as an ultimate explanation) Explaining pregnancy sickness: Proximate – hormones, heightened sensitivity to certain odours & tastes (mechanisms) Ultimate – this heightened sensitivity prevented damage to embryos (function); offspring were more likely to survive and pass on this same capacity (evolutionary origins) A full account of the phenomenon requires both proximate & ultimate explanations (and consideration of evolutionary origins can inform hypotheses about mechanisms) Proximate & ultimate explanations of psychological responses Why do we feel aversion to these things? faeces rotting meat open wounds These things are disgusting; they make us feel aversion → Why do we feel disgust? Why does this response exist in the first place? Human intuition can get in the way of psychological science, with explanations often not going beyond the proximate level William James (1890) recognised the need to probe further Not one man in a billion, when taking his dinner, ever thinks of utility. He eats because the food tastes good and makes him want more. If you ask him why he should want to eat more of what tastes like that, instead of revering you as a philosopher he will probably laugh at you for a fool. To the metaphysician alone can such questions occur as: Why do we smile, when pleased, and not scowl? Why are we unable to talk to a crowd as we talk to a single friend? The common man can only say, “Of course we smile, of course our heart palpitates at the sight of the crowd…” Evolved psychological adaptations Pregnancy sickness Disgust (and other emotions) Ability to perceive kin, people’s traits, social categories… …these are examples of hypothesised evolved psychological adaptations, ‘designed’ over millions of years of natural selection (We will see what this means for social psychology) Proximate and ultimate explanations Padlet link Heredity vs heritability Evolutionary psychology proposes the existence of adaptive mechanisms that most typically developing humans possess via heredity → At the same time, their development usually depends on environmental input (e.g. language may be an adaptation, but children require linguistic input to develop language) This is distinct from behavioural genetics explanations of individual differences → Heritability refers to proportion of variation that can be explained by genetic variation, and this can be quantified – e.g. approximately 50% of variation in intelligence can be explained by variation in genes  An overly simplistic view Genes Behaviour (genetic determinism) Physiology & Genes Behaviour psychology A more accurate view (interactionist) Environmental input Situational factors during development ‘Mid-level theories’ inform psychological hypotheses Theory of evolution by natural selection is about changes in populations over generations This does not always translate directly into psychological hypotheses There are many ‘mid-level’ theories that bridge the gap between natural selection and psychological hypotheses Important mid-level theories Kin selection theory (Hamilton, 1964) ▪ Altruistic behaviour that benefits a close genetic relative (e.g. offspring, sibling) can evolve if the benefit (× relatedness) outweighs the cost Reciprocal altruism theory (Trivers, 1971) ▪ Altruistic tendencies that benefit potential reciprocators can evolve; tendencies to detect and punish cheaters may also evolve Important mid-level theories Parental investment theory (Trivers, 1972) ▪ The sex that invests more in order to reproduce is choosier when selecting mates; the other sex is less choosy and more competitive Inbreeding avoidance ▪ Inbreeding (producing offspring with close kin) can reduce reproductive success – known as ‘inbreeding depression’ (Charlesworth & Willis, 2009); tendencies to avoid inbreeding likely evolved Does evolutionary psychology imply that we always behave adaptively? When environments change too quickly, species can go extinct because they are maladapted Until ~10,000 years ago, humans lived in small hunter–gatherer bands, and many fundamental psychological processes evolved in response to that past environment In ancestral environments, food was not reliable, there were dangerous animals around, and people depended on others in their group for survival How adaptations may lead to maladaptive outcomes today We have a weakness for sweet, salty, fatty foods (which was adaptive in the past) We still display ancestral fears (e.g. snakes, spiders, heights) We still draw lines between ‘us’ (ingroup) and ‘them’ (outgroup), favouring ingroup members and discriminating against outgroup members The ‘reality’ that we experience is a construction of our minds This does not mean that there is no objective reality or that we can be conditioned to experience reality in any random way We are trying to understand how psychological processes that evolved in humans shape our perceptions, cognitions, and emotions In particular, we are interested in processes underlying social perception and cognition From an evolutionary perspective… ‘…contribution to reproductive success is the sole criterion by which evolution by natural selection acts. Hence, the evolutionary test for a cognitive mechanism is that it generate adaptive behaviour, not that it represent truth’ (Kurzban & Aktipis, 2007, p.133) ‘…the human mind shows good design, although it is design for fitness maximization, not truth preservation’ (Haselton & Nettle, 2006, p. 63) ‘...natural selection does not favour veridical perceptions’ (Hoffman, 2016, p. 158) We perceive and make sense of reality in ways that are most adaptive for us, even if this means that our perceptions are incomplete and/or inaccurate What are the implications for how we perceive the social world? Perceiving the world, others, and the self We often need to make quick judgements based on incomplete/ambiguous information ▪ Is that a snake or just a branch? ▪ Is that stranger dangerous or harmless? ▪ Am I competent enough to do this task or not? Your perceptions/judgement may be correct or incorrect, with different consequences How does evolutionary reasoning help us understand this process?  A physiological example: Immune responses Antigen from pathogen Antigen from pollen Immune response 1. True positive: 2. False positive: (sneezing, Body deals with Body reacts to harmless inflammation) pathogen substance No immune response 3. False negative: 4. True negative: Body does not deal with Correct non-response pathogen What kind of immune system actually evolved? In the case of immune responses, false negatives are more costly than false positives → natural selection of immune system that minimises FNs at the cost of more FPs (an overly sensitive system with a low threshold for responding to potential antigens) This results in a high TP rate but also many FPs, producing responses that seem to serve no function (e.g. allergies)  A psychological example: Inferring disease from cues The disfigurement is a The disfigurement is a symptom of contagious birthmark disease Infer disease and avoid TP: Avoid diseased FP: Avoid healthy person person person (and avoid who happens to have a catching disease) scar Not infer disease and FN: Not avoid diseased TN: Correct non- not avoid person person (and possibly response catch harmful disease) If one type of false response is more costly, natural selection may have favoured a ‘disease-inference system’ that minimises the more costly false response In general, false negatives (not avoiding diseased person) are more costly than false positives (avoiding healthy person) Thus, the disease-inference system may have evolved to be biased toward FPs → We may frequently ‘see’ diseases in other people based on invalid cues Responding to a harmless feature as though it were a disease cue is sort of like a ‘psychological allergy’ This may explain appearance-based stigma (e.g. Van Leeuwen et al., 2015) Perceptual and cognitive systems may have evolved to be biased When judgements or inferences are based on ambiguous information, errors are inevitable (false positives, false negatives) If one type of error is more costly, the system will have evolved to be biased toward the other type of error This idea is known as error management theory (EMT) (Haselton & Buss, 2000; Haselton & Nettle, 2006)  Egg or not egg? Object is egg Object is not egg Treat it as an egg True positive: False positive: Protect egg Protect non-egg object Don’t treat it as an egg False negative: True negative: Fail to protect egg Not protect non-egg object  We see the same principle in engineering Smoke from harmful Smoke from harmless fire source Sound the alarm True positive (hit) False positive (false alarm) No alarm False negative (miss) True negative (correct rejection) Can error management theory explain misperception of sexual interest? More specifically, can it explain the male sexual overperception bias? (Haselton & Buss, 2000) The person is sexually The person is not attracted to you attracted to you You infer that the True positive: Match is False positive: You make person is attracted to made an unwanted advance you and ‘make a move’ You do not infer that False negative: You miss True negative the person is attracted an opportunity to you Reacting fearfully to venomous animals FN – fail to react fearfully to venomous animals FP – react fearfully to harmless animals FNs are more costly Bias toward reacting fearfully to snakes, spiders, and anything that resembles them Perception of social categories (especially harmful outgroups) FN – fail to detect actual dangers posed by outgroups FP – assume harmless social categories are dangerous FNs may be more costly Bias toward perceiving certain social categories as ‘outgroups’ and being wary of them (we often mistake social categories for tribal markers) Inferring agency when explaining outcomes FN – fail to detect actual agency FP – assume agency where none exists FNs may be more costly Bias toward inferring agency (believing that someone deliberately caused natural and random events – e.g. bad weather, crop failure, disease) This may explain supernatural, paranormal & religious beliefs Beliefs about one’s own positive qualities FN – fail to recognise one’s talents FP – falsely believe that one is talented FNs are probably more costly (because they may prevent people from benefiting from their real talents) Bias toward believing that one is talented (more than is warranted) Lots of evidence for positive illusions regarding the self Errors and biases Psychologists have identified many ways in which our minds seem prone to error and bias, which were initially believed to reflect limitations of cognition Error management theory suggests that these are not necessarily cognitive failings – they may be design features of the mind What do you think? Functional biases Padlet link