E VOLUTION 2.2 Genetics and behaviour

Evolution Charles Darwin’s theory of evolution The environment challenges the individual Which leads to that those who adapt best to the environments challenges will have a greater chance of surviving, giving offspring, and so pass on their genes to next generation.

The theory of natural selection Charles Robert Darwin 12 February 1809 – 19 April 1882

Survival of the fittest One develop characteristics that are suitable for the environment - adaption

DARWIN AWARDS FAVORITE QUOTE! "Just think how stupid the average person is, and then realize that half of them are even stupider!" --George Carlin

Darwin laid the foundation for psychologist and biologist to study animals – to get more insight about humans

LanguageLanguage 1 Mate selection 2 Facial expressionsFacial expressions 3 Examples of what one can study using animals (and mostly primates)

Evolutionary psychology Genes mutate, those that are advantageous are passed down through a process of natural selection They try to explain how we have developed over time and why

N ATURAL SELECTION CANNOT SELECT A BEHAVIOUR ! C AN ONLY SELECT MECHANISMS THAT PRODUCE BEHAVIOUR

One example of evolutionary research The study of emtions: Fessler (2006) did research on disgust

Study on disgust Fessler argued that disgust allowed our ancestors to survive long enough to produce offspring.

Fessler study on disgust Fessler Investigated the nausea experienced by women beginning of their pregnancy During this period an infusion of hormones lowers the expectant mother’s immune system so as not to fight the new foreign genetic material in her womb. His theory: maybe the nausea response helps to compensate for the suppressed immune system

Method 496 pregnant women, Let them consider 32 potentially stomach- turning scenarios Let them rank how disgusting they were Example: sticking a fish hook through their finger

Disgust Another study by Curtis et al. (2004) who carried out an online test to test whether there are patterns in people’s disgust responses. Try it now: science/humanbody/m ind/surveys/disgust science/humanbody/m ind/surveys/disgust

Results of the studies Fessler Women scored higher in the beginning of their pregnancy and the ones having morning sickness scored high on the ones involving food. Natural selection may have helped compensate for the increased susceptibility to disease during this risky period in pregnancy, by increasing the urge to picky about food Curtis Disgust was stronger for those images which threaten our immune system – women showed higher which supports the first study as well Disgust decreased with age

Evolutionary psychology Weaknesses: They see what they want to see – confirmation bias. Difficult to test the theories Little know how it really was back in time – hypothetical Underestimate the role of culture in shaping behaviour

Article for next class Read the article Eugenics revisited 1.Come prepared to discuss the article on Wednesday 2.come up with at least two discussion questions for the class to discuss