Psychology: -natural Selection Essay

Submitted By panettoncino
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Pages: 9

Lecture 1

Evolutionary Psychology

Evolution By Natural Selection Biology: -Cheetahs
-Mutation that allows it to go 2-3 mph faster than others --> slightly better chance at catching gazelles --> better chance at living -Genes are more likely to show up in the next generation -Evolutionary arms races -Peacocks Why does the male peacock have the exotic features? -Special case of natural selection called sexual selection -In sexual selection, the females of the species have certain preferences more than other features so the males that exhibit those features are more likely to mate and therefore their genes are more likely to be passed on -Are you able to impress the female of your species or not? -Organs -Heart --> selected by natural selection to pump your blood -We think of these as adaptations for surviving -Light bones -Perception -Cognition -Social Cognition -Many aspects of your Psychology are adaptations, studying it from an evolutionary point of view
Which Face is More Attractive? -One of the right is more attractive due to symmetry -Our sense of attractiveness when we look at a person's face (hot or not) is an evolutionary adaptation -"Hotness" - reproductive fitness -Genes, health, age, hormones
-Symmetry of the face is one of visual cues that we use to evaluate attractiveness

Why Men Prefer Youth -Can be a Mutation leading to prefer older females -Lower chance of having kids -Lower chance of gene passed to next generation -Genes for preferring youth spread to next generation -Natural selection

Selection Pressures On Women -Women are interested in a much broader range of ages -Quite a division of labor in our evolutionary past -More resources, better chance of success of raising kids -Male fertility declines little with age -Environment of evolutionary adaptiveness -Pleistocene: 2.588 million BP to 12,000 BP (BP = Before Present aka years ago)
-Year that most evolutionary psychologists think that selection pressures that operate in us were there

Waist-Hip Ratio -Smallest part of waist: largest part of the hip -Sexual dimorphism (difference between men and women) -Women: more fat in gluteofemoral area (rear and the thighs) -Women: less abdominal fat -Men get it in abs and neck -Attractive: WHR (Waist Hip Ratio) of 0.6-0.7 is most attractive -Cross cultural -Western men -Playboy: 0.68 +/- 0.04 -Japan, China, Uganda, Kenya, Ecuador all agree on this WHR -Independent of culture/independent of race -Due to natural selection -Not BMI -BMI: measure of overall weight -What is the selection pressure? -Not fertility -Not survival -Long-chain polyunsaturated fatty acids -Preferentially stored in rear and thighs -DHA (helps brain health and general health, capsules) -LCPUFAs: gluteofemoral fat -LCPUFAs: 20% of dry brain weight -WHR --> Higher blood DHA - +mom DHA --> + kid IQ - Maternal depletion -During the last trimester of pregnancy, brain of fetus is growing so fast that the woman cannot eat enough DHA to support growth so she must have stored DHA already --> makes it possible for the brain of the fetus to develop normally -Health of the offspring and how likely it is that THEY will succeed in life -Parity --> lower GF fat, DHA -IQ decreases with birth order -Natural Selection for GF fat -Fetal & infant neurodevelop -"hot" = better infant brain

WHR & Child Cognition -As WHR of mother goes from ideal .7-.9, the cognitive performance of the child drops END


WHR & Child Cognition
WHR & Mother Cognition
-Not only does WHR on this axis correlated with cognition of child, it is also correlated with cognition of the motion
-Low WHR protects teen mother if she has a child in early