Evolutionary Psych

Question 1

is personality just for people?

Answer 1

• Not necessarily!
• • Study of chimpanzee behaviours identified 5 core personality traits
• – Reactivity/undependability
• – Dominance
• – Openness
• – Extraversion
• – Agreeableness
• – Possible 6th trait: methodical
• Studies like this suggest a strong evolutionary basis for human personality

Question 2

evolutionary psych

Answer 2

• All humans come from an unbroken line of ancestors who accomplished 2 tasks: surviving to reproductive age & reproducing
• We carry the adaptive mechanisms that led to ancestor’s success
• Human nature and human personality are made up of a collection of evolved mechanisms

Question 3

2 levels of evolutionary psych

Answer 3

• human nature

- individual differences

Question 4

human nature

Answer 4

• what are all people like?
• • Need to belong (adaptive – allows for resources, protection, mating)
• • Empathy (adaptive – promotes group membership and cohesion)
• • Helping/altruism (enhances inclusive fitness of helpers -> more likely to help those closely related)
• • Universal emotions (strong evolutionary basis; adaptive – signal to other individuals re: pleasure, plan; used for manipulation, etc. -> happiness, sadness, anger, fear, surprise, disgust, contempt)
• These are seen in other mammals too

Question 5

individual differences (and their sources/perspectives)

Answer 5

• how are people different from one another? Why are people different from one another?
• Most challenging level of analysis
• 4 evolutionary perspectives on individual differences:
• • Environmental triggers of differences
• • Contingencies among traits
• • Frequency-dependent selection of traits
• • Optimal variance over time

Question 6

environmental triggers of differences

Answer 6

• individual differences result from environmental differences acting on species-typical psychological mechanisms (ie. Human nature)
• Ex. Individual differences in neuroticism may result from differences in stressors and demands in the environments

Question 7

contingencies among traits

Answer 7

• individual differences result from contingencies among traits; other traits (ie. Physical) may make the expression of certain psychological traits more adaptive
• Ex. A quick temper may be advantageous if one is big and strong, but not if one is strong and weak -> aggression is “reactively heritable” because it’s a secondary consequence of a different heritable trait
• Ex. Extraversion may be more advantageous if you’re strong and physically attractive

Question 8

frequency-dependent selection of traits

Answer 8

• the reproductive success of a trait depends on its frequency relative to other traits in a population (as a trait/strategy becomes more common, it becomes less successful, and vice versa)
• Ex. If most people are cooperative, selection may favour infrequent cheaters; once cheating becomes too frequent, it becomes more difficult (perhaps due to adapted response from cooperators) and frequency of cheating goes down

Question 9

optimal variance over time and space

Answer 9

• variations over time and space (ie. In environmental conditions) can favour certain traits over others -> this creates heritable differences in personality that are maintained in the population
• Ex. During food scarcity, selection favours risk-taking; during food abundance, selection favours more cautious disposition
• Ex. During a disease outbreak, selection favours low openness (and vice versa)
• Both traits in both examples become common in a population over time

Question 10

evolution of the Big 5

Answer 10

• maintained over time due “balancing selection”: genetic variation is maintained by selection because different levels of a trait are adaptive in different environments -> optimal variance over time and space
• Personality factors can be understood as clusters of key features of “adaptive landscape” of other people

Question 11

what does it mean that “personality factors can be understood as clusters of key features of ‘adaptive landscape’ of other people”?

Answer 11

• Humans have evolved “difference-detecting mechanisms” designed to notice and remember individual differences that have most relevance for solving social adaptive problems
• Relevant clusters of traits for social adaption:
• • Likely to rise in hierarchy -> extroverts
• • Likely to cooperate -> agreeableness
• • Likely to be reliable -> conscientiousness
• • Likely to drain resources -> neuroticism
• • Likely to give me good advice -> openness

Question 12

3 key premises of evolutionary psych

Answer 12

• domain specificity: adaptations are designed to solve particular problem (ex. preferences for caloric-rich foods keeps us alive, but doesn’t help with mate selection)
• numerousness: humans have many adaptations
• functionality: psychological mechanisms designed to accomplish particular adaptive goals (ex. preference for healthy mates can be traced back to adaptive advantage)

Question 13

evolutionarily-predicted sex differences

Answer 13

• say that the sexes will differ in those domains where women and men have faced specific adaptive problems, for example:
• • aggression: higher in men because they’ve had to do more to attract mates evolutionarily (women invest more; are choosier)
• • jealousy: men more likely to get jealous if women have sex with someone else (unsure of paternity), women more likely jealous if men invest emotionally/financially in someone else (loss of resources)
• • mate selection: men care more about physical attractiveness (indicates fertility), women care more about financial resources (to support offspring)

Question 14

ADHD as an adaptive trait?

Answer 14

• ADHD appears maladaptive, but why is it so prevalent?
• advantageous in evolutionary past -> being restless was adaptive; helped nomads survive
• Linked to the 7R gene, which is associated with more risky and restless behaviours in general -> people whose ancestors travelled further out of Africa more likely to have it

Question 15

depression as an adaptive trait?

Answer 15

• analytic rumination hypothesis: depression is triggered by complex social problems related to fitness and survival -> forces you to ruminate and try to solve it
• support for ‘social problems’ aspect: depression often triggered by social stress and interpersonal conflict, and affects women more
• support for ‘problem-solving’ aspect: depression activates prefrontal cortex and allows you to focus on rumination and problem-solving

Question 16

limitations of evolutionary psych

Answer 16

• based on inferences (can’t go back in time to know for sure what the evolutionary causes of behaviour were)
• limited understanding of nature, details, and design of evolved psychological adaptations
• what might have been adaptive in the past may not be adaptive today
• easy to come up with competing hypotheses
• hypotheses are sometimes untestable/unfalsifiable