ch 8 PSYCHOLOGY OF PERSONALITY

Evolutionary Psychology

patterns of behavior that are part of human nature; originated in the way that promoted survival and reproduction

Behavioral Genetics

addresses how individual differences in personality are passed from parent to child & shared by biological relatives

every human being is part of an unbroken chain of winners

our ancestors survived to adulthood, found mates, & had children who also survived, continuing the lineage

way human behavioral patterns develop

our long-ago ancestors found certain behaviors helpful or necessary for survival

evolutionary mismatch

not all the results of evolution are useful in the modern environment; can lead to deficits in psychological & physical functioning such as postpartum depression

the environment humans evolved to our present form

in hunter-gatherer societies roaming the African savannah

agression and altruism

the two sides of many human behaviors, examined through the evolutionary lens

the role of the instinct toward aggression in humans

it can be necessary for survival in certain situations, but it may also have a harmful effect leading to fighting, murder

benefits of aggressiveness for individuals in social groups

help protect territory, property, and mates, potentially leading to dominance and higher status within the group.

the negative outcomes that can result from aggressiveness

can lead to fighting, murder, and large-scale violence, such as war.

altruism and it’s relation to fitness

tendency to aid and protect others, especially close relatives, and may enhance inclusive fitness by supporting the survival of shared genes.

Sociometer theory

feelings of self-esteem evolved to monitor an individuals level of acceptance & value by others

ways low-esteem affects behavior according to sociometer theory

when feeling undervalued and unaccepted, our self-esteem may decrease; motivates us to engage in behaviors that improve others’ perceptions of us, which enhances our self-esteem

a trait that was once maladaptive

can become vital for survival at the species level, environmental changes can make previously irrelevant traits crucial for survival.

example illustrating adaptation

White moths became easy prey for birds due to their visibility, while darker moths survived and propagated, demonstrating how coloration affected survival based on environmental conditions.

ways the adaptability of a trait vary

A trait that is beneficial in one context may become harmful in another, highlighting the complexity of adaptation.

life history strategy (LHS)

encompasses different kinds of adaptations related to reproduction and offspring care.

characterizes a fast-life history strategy

Animals with this strategy reproduce multiple times at a young age but invest little to no resources in protecting their offspring, which may enhance reproductive success.

define a slow-life history strategy

Animals with this strategy reproduce later in life, have fewer offspring, and typically invest extensive resources in raising them, with safe, predictable environments promoting ppl who marry late, have few children, and put extensive resources into raising them

ways behavioral patterns relate to environmental experiences in evolutionary psychology

evolve as reactions to environmental experiences, shaping how individuals adapt to their surroundings.

people who may have evolved a repertoire of behavioral strategies

may possess multiple possible behavioral strategies that they can employ depending on the context and environmental demands.

frequency-dependent selection in evolutionary psychology

Some evolved traits may adjust their prevalence based on how common they are in the overall population, influencing individual differences.

the main criticism of the evolutionary approach to human behavior

faces controversy and misunderstandings, leading to various criticisms that serve as "stress tests" for the theory.

the purpose of the five criticisms in the context of evolutionary psychology

Each criticism acts as a "stress test" to evaluate the robustness and validity of evolutionary psychology as a framework for understanding human behavior.

the first challenge in testing evolutionary speculations

is how to test evolutionary speculations, as many traits may not clearly show adaptive advantages.

example to illustrate that not all genetically influenced behaviors are adaptive

The vast majority of stepparents are not abusive, suggesting that not all behaviors have an adaptive advantage.

ways evolutionary theorists respond to challenges in methodology

argue that alternative explanations are always possible and acknowledge that complex evolutionary theories are difficult to prove or disprove in their entirety.

the second challenge regarding the reproductive instinct in evolutionary psychology

is the assumption that evolutionary psychology implies everyone is trying to have as many children as possible.

modern behaviors like using condoms challenge the idea of a universal reproductive drive

The use of birth control methods, specifically to avoid having offspring raises questions about the idea that all individuals are driven to reproduce.

this criticism misunderstand the nature of evolution

overlooks the fact that while individual choices vary, the overarching principle of evolution is that you wouldn't be here unless your ancestors successfully reproduced.

the third challenge regarding conservative bias in evolutionary psychology

the belief that the current behavioral order is both inevitable and appropriate, suggesting that it cannot change.

ways evolutionary theorists respond to the criticism of inevitable behavioral order

argue that such objections are irrelevant from a scientific standpoint and do not accurately reflect the complexities of evolution.

the "naturalistic fallacy" that opponents of evolutionary theories may commit

is the belief that anything shown to be natural must also be good, which oversimplifies the relationship between nature and morality.

the fourth challenge regarding human flexibility in evolutionary psychology

the perception that evolutionary accounts suggest many behaviors are genetically programmed and cannot be changed by conscious thought.

ways evolutionary psychology address the idea of built-in behavioral patterns

It acknowledges that the evolution of the cerebral cortex has enabled humans to respond flexibly to changing circumstances and to overcome innate urges.

the difference between the modular approach and the flexibility approach in evolutionary psychology

The modular approach suggests specific, genetically programmed behaviors, while the flexibility approach emphasizes the human capacity to adapt and change behaviors based on context and reasoning.

the fifth challenge regarding biological determinism in evolutionary psychology

that behavioral phenomena may result from humans responding to changing circumstances rather than solely from evolutionary history.

Eagly and Wood argument about mate preferences

females often value a male's wealth and power more than his looks, while a male's interest in a female's wealth is typically lower.

ways changing social circumstances affect sex differences in mate preferences

When females have power equal to males, the differences in preferences for a wealthy spouse between genders become much smaller, suggesting a social influence on behavior.

Research on genetic bases of behavior

suggests that traits such as intelligence, poverty, criminality, mental illness, and obesity are genetically fixed

Eugenics

idea that humanity could be improved through selective breeding

Cloning

belief that it might be technologically possible to produce a complete duplicate (psychological as well as physical) of a human being

Genetic confounding

arises when trying to understand the effects on development that parenting styles and childhood environments do and do not have

assumption

traits and behaviors influenced by genes should be more similar among more closely related people

• monozygotic (identical) vs dizygotic (fraternal) twins

heritability coefficient

degree to which variance of the trait in the populations can be attributed to variance in genes.

• variance of the traits refers to how traits vary between individuals

average heritability of many traits is

.40, 40% of the variance is accounted for by genes

siblings who share 50% of the variable genes

also does not necessarily describe the similarity between any particular pair of brothers and sisters

two full siblings could

share none of the variable genes at all or share all of them

not all of personality

comes from experience, some of it comes from genes

heritability estimates

show that genetic factors often influence traits

greater than zero in heritability

indicates a genetic contribution to the trait

challenges the assumption

that traits are solely shaped by environmental factors

genes matter

personality is not solely determined by environmental factors

early environment and its shape of personality development

traits of biological siblings resemble each other with average correlation of .16

• adoptive siblings raised in the same family resemble each other with a correlation of .04

shared family environment

important in the development of conduct disorder, anxiety, and depression

heritability can’t tell you

nature vs nurture

traits with little variation

will have heritability close to zero (example. number of arms)

can’t use heritability

to determine what percent of a traits is determined by genetics and by the environment

heritability statistics are not

the nature-nurture ratio

• a biologically determined trait can have a zero heritability

heritability can’t tell you

how genes affect personality

heritability statistics do not

tell you much about the process by which genes affect personality and behavior

• watching tv is heritable

• divorce is heritable (if close relative have been divorced, you are more likely to get divorced)

molecular genetics studies

claimed to have found single genes responsible for important behavioral outcomes

• one gene doesn't;t tell the whole story, or even much of the story

genome wide association studies GWAS

look for associations between hundreds of thousands of genes or patterns of genes and personality in large samples

epigenetics

explores how experience, especially early in life, can determine how or even whether a gene is expressed during development

• environmental factors can lead to inhibit the expression of certain behavioral genes

genes are not causal

they only provide the design

environments can

affect heritability

nutrition and height

heritability will be higher when all children have the same level of nutrition, but lower when nutrition differs

intellectual stimulation and educational opportunities can

increase IQ

evocative person-environment transaction example

a child who inherits a genetically based tendency to be easily angered can tend to create & thereby experience hostile social situations

active person-environment transaction example

a person who inherits a predisposition towards sensation seeking may take drugs, people who are physically attractive and strong are relatively likely to be extraverted

reactive person environment transaction example

stressful environment can lead someone to genetically predisposed to develop mental illness but leave other individuals fine

genes and the environment interact in complex ways

shaping behavior dynamically

role of epigenetics

experiences can modify gene expression without changing DNA sequences

genetic influences is

not predestination or indicate behavior in a fixed way

• the environment can reinforce or counteract genetic tendencies over time

understanding genetic predispositions can

help tailor environments for better psychological and behavioral outcomes