Lecture 11 Explaining Personality Flashcards
Evidence that personality traits might be adaptive traits?
- early wolf human interactions lead to the domestic dog
- maybe neuroticism/conscientiousness/openness - survival
- extra version/agreeableness - reproduction
Could personality be neutrally selective?
Selective neutrality
Analogy:gut packing design - everyone’s different but it doesn’t even matter
But… If personality is really fitness neutral, then personality variation should not predict fitness relevant outcomes… But they do!
What does the balancing selection theory say?
That there are multiple selection pressures influencing the evolution of single traits
Nettle - identified major trade offs for each of the big 5 - but all of these MUST be in perfect balance so that none of the traits are winning…
Environmental heterogeneity - more plausible - says that the environment may contain different niches that favour diff kinds of behaviour.. So not all pressures are acting at once
What was the Camperio data that was congruent with balancing selection?
Family history of Italians who were island dwellers vs coastal mainlanders
Those who had been on island for 20+ generations had lowerlevels of openness and extra version that mainlanders and people who had been there more recently
What is frequency dependent selection?
An example is the hawk dove game…
Where they pursue diff strategies than each other.
None of them is stable.. Only stable relative to each other..
Might explain personality traits.. Eg agreeable people may be easy to take advantage of.. But without them everyone would be exploiting everyone else
What does life history theory suggest?
That were balancing an energy budget
Principles :
- resources vary in their availability over time
- fitness maximisation can be through long vs short term strategies
- trade offs must be made …. Reproduce now or later… Quantity over quality???? Etc
What does the simulation study show for the life history theory?
Thorough exploration - increases likelihood of finding high quality resources.. But delays reproduction
TRADE OFF
Evolution of individual diffs through exploration intensity
Found that super filial foragers are more affressive and bold - more to GAIN
Thorough explorers - more to LOSE
What is the evolution of personality also mediated by?
Genetics
Biology
Cognition
Social / situational context
How does genetics play a role in personality?
genetics plays a 40-50% role in variation
Human genes are polygenic, however, so it’s hard to know which genes do what.
Found no genes for personality so far, but have for schizo
Can do candidate gene approach - look for 1 gene
Gene wide association studies - scan entire genome for associations with a given trait
Brain structure and function and personality?
Methods: psychopharmacology, MRI, EEG
Found support for predicting a regarding brain structure for 4 of the big 5 traits
Extra version - reward processing areas
Neuroticism - threat processing and emotion function areas
Agreeableness - social info processing areas
Conscientiousness - regions associated wit planning and self regulation
Cognitive mechanisms and personality?
Don’t need to find biological cause for all things…
- attentional bias - dot probe
Extroverts predicted probes faster when they were in area of positive word
Opposite for neurotic people
Can train bias away from negative word and towards positive word
Social context and culture and personality?
50-60% variation due to environment
But hard to tell if influence of culture on personality… Or if it’s culturally endorsed biases and stereotypes.
Social context:
Model. Social enviro, others behaviour all interact to influence behaviour…
A test - pairs of participants interacted for 5 minutes .. Recorded…. Patterns of findings found that social reputation interacted with targets personality….
Culture influences and personality?
Can be characteristic adaptions - aspects of personality concerned with time, role and place are, by definition in social context and culture
Trait expressions - display rules - more display rules in JAPAN
What are some hints that personality might partly reflect phylogenetically old processes?
- cross cultural data - big 5 consistent
- cross species data - big 5 also in chimpanzees (correlated suites of behaviour)
- behavioural genetics - genetic variation explains for 40-50% of the variation in personality traits
Maybe personality trades are evolved osych mechanisms … An adaption????? A by product??? Noise?
