Lecture 8 - Parents

story of Adi

• loved by mother, showered with affection but father not so kind, 

• Father wanted him to be a civil servant, Adi loved art and his mother encouraged his gentler interest

• Adi was 18 when mom was diagnosed with terminal cancer 

• Adi short for Adolph (Hitler) and grew up to be one of the most notorious mass murderers in history 

natural selection

Random variation that gets rise to differences in survival and reproduction and gets passed from generation to generation

camouflage

prey animals blend into their environment so they are harder to see by predators but Darwin thinks that there is a range of creatures that blend into varying degrees just by chance 

what problems have our cognitive mechanisms been shaped by natural selection to solve?

perceiving the world, getting nutrition and rest, selection and attracting mates, learning about our physical and social environment, making decisions, choosing our allies and enemies, figuring out beliefs and desires of others

why is the idea that natural selection is driven by spreading genes false?

false because animals arent even aware they have genes

why is the idea that everything is adaptive a misconception?

because there can be by products and accidents too

why is the idea that if something evolved its good a misconception?

its not true because all sorts of awful things are natural like cancer and all sorts of great things are unnatural like human rights, having different identities, etc

why is the idea that if it has evolved its inevitable a misconception?

genetic vs environmental causes are in principle no different cause some influences of both types may be hard to reverse while others may be easy to do so 

ultimate causation

why something came to be in the first place

proximate causation

why something is the way it is in the here and now

incest avoidance

we tend to avoid wanting to have sex with people we are closely related to, predicted by evolutionary biology because it is detrimental to the offspring since there are too many genetic mutations that occur when there are too many similar genes leading to high risk of disease and defects in offspring

how do we know who shares too many of our genes and who doesnt?

•  if you live with someone as a kid and this means that they can be sexually off-limits overtime even if you aren’t related to each other, automatic

• facial resemblance is also an indicator

sperm

small sex cell with genes and abundant

egg

Large sex cell with genes and also food and a protective cover and the metabolic machinery needed for the organism to grow

parental investment

any investment by the parent in an individual offspring that increases the offspring’s chance of surviving at the cost of the parent’s ability to invest in other offspring

• explains why smaller cell (sperm) is more aggressive than the larger one (egg)

female parental investment

their investment is usually much higher because they have to carry the fetus inside of her for many months and nurses and protects it until it has grown big enough to fend for itself for years

male parental investment

much lower investment cause all they have to do is mate with the female for a few mins

male psychology explained by sex differences

once one can fertilize many females so those who mate with many females as possible will have the most reproductive success and the genes that allow them to do so will be passed on

female choice

choosy because they want the one male whose offspring has the best chance of surviving

male competition

occurs cause they want to mate with as many females as possible, larger, typically evolved special weapons, have special displays to attract females 

if parental investment is reversed will differences in physiology and psychology be reversed too?

yes this is seen in seahorses where males are choosy cause they have larger parental investment and females compete so they are more aggressive

does extent of differences in parental investment predict extent of physiology and psychology differences?

yes because in penguins since parental investment is equal we are not able to tell them apart

what sex differences do we observe in humans?

the reason why men are bigger than women might be because they are more aggressive and they pursuit more sexually due to use of pornography and prostitution

mate preference study

people were asked what you valued in a long term mate

mate preference study results (universal)

for both men and women they valued kindness, intelligence, beauty, youth (large eyes, full lips and smooth tight skin) , health (absence of deformities, clear eyes, unblemished skin, intact teeth and average face)

what did males value more in the mate preference study?

 more focused on ability to have children

what did females value more in the mate preference study?

more focus on power, status and interest in investing in children

sexual partner study (shows cultural differences)

study that asked people how many sexual partners they want? found that men wanted more than 1 women but there are cultural differences like african males on avg wanted fewer partners than women do in eastern europe

free rider

an individual who receives but never gives, gets the same rewards as someone who shows altruism but at no cost

altruism in bats

fly out of cave and try to find a big animal to bite like a horse, they drink the blood, fly back and spit out the blood in the cave

kin selection

A gene will spread in a population if it increases the  chance that the bearer of that gene will survive or if it increases the chance that other individuals who also possess that gene will survive 

what are reason’s we behave altruistically even though that might not seem adaptive by natural selection?

due to kin selection, if we have a gene that makes us care for our offspring vs a gene that makes us care for ourselves the first will win because evolutionarily it ensures reproduction

personality

person’s general style of dealing with the world, particularly with other people

how do we judge a personality test?

based on reliability and validity

reliability

how well the test keeps giving us the same score

how do people differ?

gender identity, sexual preference (biggest difference between men and women), happiness, mental illness but most importantly is personality and intelligence  

what were the categories of the early personality trait theories?

neurotic or stable, introverted or extraverted

what are the categories of the big five?

openness to experience, conscientiousness, agreeableness, extraversion and neuroticism 

• test is reliable and agreed upon many observers

what components make up intelligence?

Abstract reasoning, problem solving, memory, mental speed, knowledge, mathematical competences, knowledge, creativity

g

general intelligence factor of an IQ test

s

specific ability factor of an IQ test

how does an IQ test work?

• Each part (specific ability) of the IQ test gives you a score but on top of this there’s a general factor that sums everything up into one score (g)

• All raw scores are converted into standardized scores, normally distributed, mean of 100 and standard deviation of 15

• Above and beyond specific scores there will be a g, how your numbers coalesce 

cult of smart

world where the best jobs are given to people who graduate from universities, to get a manicurist or other job you still need to go through college (shows that to some extent IQ matters so much because we want it to)

heredity

• proportion of variance due to genetic differences not the proportion of an individual’s trait that is due to genes (scored from 0 to 1)

shared environment

proportion of the variance due to environment by family members

what factors influence differentiate one individual from another?

heredity + environment (shared + nonshared)

non shared environment

proportion of all other variance (random events)

differences in monozygotic, dizygotic twins and adopted children

If monozygotic twins are way mor similar than dizygotic then there is a big role (opposite case, low role in genes in heritability) 

• Are adopted children highly similar to their brothers and sisters? (if yes than high role in shared environment

• Are twins reared apart very similar (if yes than high gene role)

what are the 2 big findings in behavioral genetics?

• High heritability for everything pretty much 

•  almost all of the rest is due to a non-shared environment so the shared environment doesn’t mean much

do group differences have to be largely due to genes?

no cause IQ differences correspond to socially defined groups, not genetic groups and we know that IQ can differ radically across groups without any genetic differences 

flynn effect

found that we are getting smarter overtime, argument that differences are much smaller showing that cultural changes are that because cause not enough time has passed to be a genetic cause

what is a limitation involved in the studies done that came to the findings of behavioral genetics?

they were done in middle class families and children so if the same thing was done in lower class families with poor environment then environment would have a greater impact

heredity takeaways

• The better the environment the more role genes will play and the greater the heritability of a trait will be 

• The worse the environment the less the genes have the chance to max out their potential and the greater the role of environmental factors will have in accounting for differences between different individuals

nurture assumption controversy

• argues that we are mistaken in believing that parents shape children 

if the nurture assumption controversy is true why do good parents have good kids?

• 1: parents do something that affects their kids

• 2: parents share genes with the kids (right because if you never met your parents you would discover they are much like you)

• 3: the child is making the parents good, not vice versa