Evolutionary Psychology Human examples: - Skin color - Tail bone How humans think and behave is also a product of evolution Darwin: Evolution by Natural Selection • • • • Variations among organisms Struggle for survival because all cannot survive Those with traits leading to greater survivability and reproductive success more likely to have more descendants These descendants were more likely to embody traits that led to survival. Sexual Selection • • • • • • • The ability to attract mates is integral for the selection of certain traits Males developed more aggression, sharper teeth, horns, antlers and other physical traits to compete for females Personality traits in both sexes have also developed as a means to attract the opposite sex. Sexual selection is not individual, but rather collective Inclusive fitness- the idea that biological selection may not only apply to the most fit individuals, but may be selected because they enhance the overall fitness of related individuals. Kin Selection- “Inherent and inherited predisposition to act altruistically for relatives” Those related to you share many common genes, enhancing survival of relatives increases chances of survival of those same genes. Selfish Gene Theory- from the fittest individual to the fittest gene Reciprocal Altruism • • • Kin selection proposes one type of altruism based on the selfish gene. Robert Trivers proposed another type called Reciprocal Altruism not based on genetics Example: Two unrelated hunters share food, so when one could not provide for himself the other would supply food with the expectation that the favor would be returned when necessary People prone to be nice had a better chance of survival Misconceptions about Evolutionary Psychology • • • We have been optimally evolved to our current environment We are consciously trying to maximize the survival of our genes Evolutionary psychology proposes genetic determinism Mate Selection • • • • • The mechanism that facilitates sexual selection Mate selection can be much more arbitrary than natural selection but it is surprisingly consistent Acknowledges that selection in humans is in the mind and not just the body Preference for a heritable trait by mates makes a positive feedback loop that passes the heritable trait on to future generations Mate selection and sexual selection became apparent because of traits that are “extreme, striking, and costly that are attractive to the opposite sex and that have little apparent survival value” Human Mating Preferences • • • Men prefer looks over resources and women prefer resources over looks Many traits that are preferable to the opposite sex are fitness/reproductive health indicators (i.e. men with big muscles, women with the preferred 0.7 waist to hip ratio) These traits have clear survival value or indicate fertility which make them preferable from evolutionary standpoint
