Week 5 - Evolutionary Psychology

Terminology

• Byproducts of adaptations: incidental effects of adaptations not considered as adaptations (e.g., belly button)
• Adaptive: reliably allows species to adapt and reproduce
• Exaptations: adaptations that initially arose for one function but were co-opted for another function (e.g., antisocial personality/drinking alcohol)
• Desirable: a judgment aspect, not a criteria for adaptation
• Spandrels: features that did not arise as adaptations but as side effects of adaptive processes (e.g., by-products of a large brain: reading/writing/fine arts)

Survival

• Living long enough to pass on genes
• Competition with others of the same species is crucial
• Don't need to be the best, just better than the next person (survival of the fittest)

Reproduction

• Producing offspring is the single most important factor in natural selection
• Functional adaptations are designed to accomplish particular adaptive goals

Personality Psychology

• Evolutionary perspectives: those who developed fears of certain things lived longer, reproduced, and passed on genes
• Life history theory: life requires capturing and allocating energy
• Fitness maximizing strategy: the strategy that leads to the allocation of energy that results in the greatest fitness is the one that wins out

Sex Differences

• Males and females will be the same or similar in domains where sexes have faced the same or similar adaptive problems
• Sex differences in domains where sexes have faced different adaptive problems (e.g., aggression, jealousy, desire for sexual variety, mate preferences)

Human Nature

• Human nature is a product of evolutionary processes
• Psychological mechanisms that are successful in helping humans survive and reproduce out-replicate those that are less successful
• Examples of evolutionary analysis at the human nature level: need to belong, helping and altruism, universal emotions

Individual Differences

• Environmental triggers of individual differences: e.g., father absence directing individuals toward short-term mating strategies
• Heritable individual differences contingent on other traits: e.g., individual differences in muscularity and size influencing mating strategies
• Frequency-dependent strategic individual differences: e.g., short-term and long-term sexual strategies maintained in the population at a frequency where reproductive benefits are equal

Theoretical Framework

• Preparedness hypothesis: certain things in our ancestral past posed a real threat to our survival or the survival of our offspring
• Life history theory: life requires capturing and allocating energy
• Good genes hypothesis: symmetry is an indicator of good genes, and therefore, symmetry should be more attractive

Energy Allocation

• Somatic effort: the bioenergetic and material resources devoted to continued survival of the organism
• Reproductive effort: the resources devoted to the production of new organisms
• Fundamental trade-offs: individuals can enhance their fitness in two ways, by investing in traits that affect the age schedule of morality or fertility
• Three broad fundamental trade-offs with energy allocation:
  • The present-future reproduction trade-off
  • The quantity-quality trade-off of offspring
  • Energy allocation to growth now vs. future reproduction