4. Determining Nature, Nurture, & Necessity

Question 1

Behavioural Genetics

Answer 1

The study of genetic and environmental influences on behaviour.

Question 2

Environmentalist View

Answer 2

The belief that personality is determined by socialization practices, such as parenting style and other agents of society.

Question 3

Eugenics

Answer 3

From The Textbook: “The notion that the future of the human race can be influenced by fostering the reproduction of people with certain traits and discouraging reproduction among people without those traits or who have undesirable traits.”

Question 4

Percentage Of Variance

Answer 4

Refers to the fact individuals vary, and this variability can be divided into percentages of different causes of the veriability.

But, typically, not nearly the only thing behavioural geneticists want to figure out, they also want to look at the environment.

Question 5

Heritability

Answer 5

The proportion of observed variance in a group of individuals that can be accounted for by genetic variance.
In essence/more formally, heritability is the proportion of phenotypic variance that can be attributed to genotypic variance

Question 6

Phenotypic Variance

Answer 6

Observed individual differences

Question 7

Genotypic Variants

Answer 7

Individual differences in the total collection of genes in each person

Question 8

Environmentality

Answer 8

The percentage of observed variance in a group of individuals that can be attributed to environmental/non-genetic differences.

Question 9

Misunderstood Things About Heritability

Answer 9

1. Heritability cannot be applied to a single individual
2. Heritability is not constant, it is a statistic that applies only to a population at one point in time and in a particular type of environment
3. Hertiability is not a precise tstatistic, it is an estimate of the percentage of phenotypic differences due to genetic differences

These are the FACTS, not the myths

Question 10

Nature-Nurture Debate

Answer 10

The discussion of whether genes or environment are the more important influence on personality.

Question 11

Family Studies

Answer 11

Research that correlates the degree of genetic overlap among family members with the degree of personality similarity. Utilizes the fact that there are known degrees of genetic overlap between different members of a family in terms of degree of relationship.

Note a con, it violates equal enviroments assumption as members of a family may be similar on a specific trait based on environment rather than genes.

Question 12

Twin Studies

Answer 12

Estimate heritability by gauging whether (genetically) identical twins are more similar in personality to fraternal twins (50% shared DNA).

Question 13

Equal Environments Assumption

Answer 13

Assumption that environments experienced by identical twins are no more similar to each other than environments experienced by fraternal twins.

Studies have consistently supported the equal environments assumption.

From The Textbook: If they are more similar, then the greater similarity of the identical twins could plausibly be due to the fact that they experience more similar environments rather than the fact that they have moregenesin common.

Question 14

Adoption Studies

Answer 14

Examines correlations between adopted children and their adoptive parents, with whom they share no genes. Compared to correlations between adopted children and genetic parents, who had no influence on the childrens’ environments.

Question 15

Adoption Studies

Assumption of Representativeness and Selective Placement

Answer 15

Assumption of Representativeness: The assumption that adopted children, birth parents, and their adoptive parents are representative of the general population (confirmed by studies).

Selective Placement: The concern that adopted children are placed with adoptive parents similar to their birth parents (no real evidence of this).

Question 16

‘Psychopathic’ traits show [answer]

Answer 16

Moderate to high heritability / substantial heritability

According to several studies

Question 17

Each Big Five trait yields heritability estimates of approximately [answer]

Answer 17

50%

Exactly 48% according to textbook, 49% according to lecture

Question 18

How heritable is sexual orientation?

Answer 18

Evidence it is moderately heritable

Question 19

Marriage and Heritability

Answer 19

• The propensity to marry is hertiable
• Hertiable personality characteristics are suggested to play a role in marriage satisfaction (especially for women, husbands’ personality did not explain as much)

Question 21

Shared Environmental Influences

Answer 21

Features of the environment that siblings share, eg. number of books in the home, whether there is a TV in the house, etc.)

Question 22

Non-Shared Environmental Influences

Answer 22

Features of the environment siblings do not share. Eg. Different peer groups

Question 23

Do shared or non-shared environmental influences affect personality more?

Answer 23

By far, non-shared environmental factors affect personality traits more.

However, research is still developing on this, since a lot of these findings have been from self-report, observational studies indicate potential other findings

Question 24

Molecular Genetics

Answer 24

Techniques designed to identify specific genes associated with specific traits (like personality traits).

Question 25

Molecular Genetics - The Association Method

Answer 25

Identifies whether individuals with a particular gene/allele score higher or lower on a particular trait measure.

Question 26

DRD4 Gene

Answer 26

Gene located on short arm of chromosome 11 (not sure if testable) that codes for a dopamine receptor (responds to dopamine, discharges electrical signal, activating other neurons). Associated with *novelty seeking*, the tendency to seek out new (and often risky) experiences. Individuals with 'long repeat' versions of the gene['s 7R allele (7R+)] showed higher rates of novelty seeking than individuals with 'short repeat' versions of the gene (long DRD4 genes tend to make people relatively unresponsive to dopamine). | DRD4 gene's 7R+ allele more common in North America than Asia ## Footnote While this has been replicated several times, there are also studies that fail to replicate. This may be because the DRD4 gene is estimated to only explain 4% of the variation in novelty seeking.

Question 27

Serotonin transporter gene 5-HTTLPR is linked to...

Answer 27

neuroticism and other depressive and anxiety related traits.

Question 28

Genome-Wide Association Studies (GWAS)

Answer 28

Rapidly examine the entire genome for links with personality.

Question 29

Polygenic Risk Scores

Answer 29

Mathematical sums of many genetic variants. Basically, looking at a ton of genes to predict the risk of having certain personality traits/having a low sense of well-being, etc. ## Footnote Complete understanding of the role genes play in personaliy may be many years away.

Question 30

Genotype-Environment Interaction

Answer 30

Refers to how the environment has a different impact depending on an individual's genotype. ## Footnote Eg. Most introverts need a low-stimulation environment to focus, whereas extraverts do well with stimulation, but make more errors when there is little stimulation

Question 31

Genotype-Environment Interaction - Abusive Parenting

Answer 31

* Abused children who had a genotype that produced low monoamine oxidase A (MAOA) far more likely to develop conduct disorders than abused children with high levels of MAOA

Question 32

Genotype-Environmental Correlation

Answer 32

The different exposure of individuals with differing genotypes to different environments/exposure to environmental conditions depends on/is affected by genotype.

Question 33

Passive genotype-environment correlation

Answer 33

Children exposed to certain environments early on based on parents both giving the child their genes and providing them with an environment based on those genes. It's not because of anything the child is doing, the parents have the genes as is and thus are providing the environment as such. ## Footnote Eg. Parents pass on genes for verbal/linguistic ability, and stock their houses with a lot of books

Question 34

Reactive genotype-environment correlation

Answer 34

Where parents (or others) respond to children differently based on children's genotypes. (Children who like to be hugged are more likely to be cuddled/hugged by parents than children who don't) ## Footnote Similar in principle to evocation.

Question 35

Active genotype-environment correlation

Answer 35

When a person with a particular genotype creates or seeks a specific environment/the heritable propensity to select environmental exposure. ## Footnote E.g. High sensation seekers expose themselves to risky environments

Question 36

Epigenetics

Answer 36

The study of how experience (i.e. environmental influences) can mediate/determine how or whether a gene is expressed in an organism. Epigenetic effects involve changes in an organism's *phenotype*, not *genotype*, as a result of something prominent in the environment. | Epigenetics: How *nurture* shapes *nature*. ## Footnote Some epigenetic changes are hertiable. Heritability estimates do not factor in epigenetic effects.

Question 37

Overall, personality characteristics are [percent] heritable and [percent] environmental.

Answer 37

Overall, personality characteristics are 30-50% heritable and 50-70% environmental.

Question 38

Cleaner Wrasse Fish | Personality Differences

Answer 38

Some fish cheat/steal mucus that they need, some do not, this is consistent over time for individual fish.

Question 39

Natural Selection

Answer 39

Variants of phenotypes that better allow an organism to survive and reproduce will lead to more descendants. Natural selection results in gradual changes in a species over time - successful variants increase in frequency and eventually spread throughout the gene pool, replacing less successful variants.

Question 40

Hostile Forces of Nature | May not be testable

Answer 40

The term used by Darwin describing any event that impedes survival.

Question 41

Sexual Selection | Definiton + Two Types

Answer 41

Evolution of traits based on mating benefits rather than survival benefits. Intrasexual competiton: Competition between one sex for mates Intersexual selection: A mate selecting a mate of the opposite sex ## Footnote This is more the general definition, not a 1:1 for humans

Question 42

Differential Gene Reproduction

Answer 42

Reproductive success relative to others. ## Footnote From the Textbook: The genes of organisms who reproduce more than others get passed down to future generations at a relatively greater frequency than the genes of those who reproduce less.

Question 43

Inclusive Fitness Theory | Maybe testable?

Answer 43

From The Textbook: Modern evolutionary theory based on differential gene reproduction. The “inclusive” part refers to the fact that the characteristics that affect reproduction need not affect the personal production of offspring; they can affect the survival and reproduction of genetic relatives as well. ## Footnote Eg. Protecting a sibling may enable them to better survive and reproduce Note this happens more the closer the relation is. (Happens more with siblings than cousins, for example)

Question 44

Adaptations

Answer 44

A reliably developing structure in the organism, that causes the solution to an adaptive problem (anything that impedes survival/reproduction). ## Footnote Hallmark: Special design (features of an adaptation are recognized as components of specialized problem-solving machinery

Question 45

Byproducts of Adaptations

Answer 45

Evolutionary mechanisms that are not adaptations, but instead byproducts of other adaptations.

Question 46

Evolutionary Noise

Answer 46

Random genetic/phenotypic variations that are neutral with respect to selection.

Question 47

Three key premises of Evolutionary Psychology | List them

Answer 47

1. Domain Specificity (specific in the sense they solve a particular adaptive problem) 2. Numerousness (numerous adaptive mechanisms) 3. Functionality (our psychological mechanisms are designed to accomplish particular goals) ## Footnote More detail for these three on individual flashcards

Question 48

Domain Specificity

Answer 48

The presumption that adaptations are engineered by the evolutionary process to solve specialized *adaptive problems*. Implies selection tends to generate *specialized* mechanisms for each specific adaptive problem.

Question 49

Numerousness

Answer 49

We have numerous adaptive mechanisms to handle the numerous adaptive problems that humans have faced.

Question 50

Functionality

Answer 50

Our psychological mechanisms are designed to accomplish particular adaptive goals.

Question 51

Hierarchy of Evolutionary Analysis

Answer 51

Top: Evolution by Selection (usually skipped by scientists/scientists move onto a different hypothesis, as this has never been disproven). Middle: Middle-level evolutionary theories (eg. the theory of parental investment *and* sexual selection [this is one single theory]). From these hypotheses, predictions can be developed and tested empirically. Bottom: Specific, testable, predictions. ## Footnote Two ways to approach this hierarchy, top-down and bottom-up. More detail on other cards. Parental Investment and Sexual Selection Theory: "The sex (female or male) that invests more in offspring is predicted to be more discriminating or “choosy” about its mating partners."

Question 52

# Hierarchy of Evolutionary Analysis Deductive Reasoning Approach

Answer 52

The top-down, theory-driven method of empiracle research. Using theories to generate predictions/hypotheses.

Question 53

# Hierarchy of Evolutionary Analysis Inductive Reasoning Approach

Answer 53

The bottom-up, data driven method of empirical research. Observing a phenomenon, then developing a theory to fit those observations.

Question 54

Need to Belong - Status and Group Acceptance

Answer 54

A central motive of human nature. Aligns with the human motives of agency and communion.

Question 55

Origin of Social Anxiety

Answer 55

Theorized to originally have been an adaptation to prevent humans from being socially excluded

Question 56

What can trigger *group cohesion*?

Answer 56

* External threats (especially intense ones) * The opportunity to acquire resources

Question 57

# Evolutionary Psychology Humans have a propensity to this darker trait.

Answer 57

Aggression, due to a lower expression of a gene that inhibits fight or flight.

Question 58

Three perspectives on

Question 59

Three distinct perspectives on the study of emotions

Answer 59

1. Examining whether facial expressions are interpreted the same across cultures (universality is a criterion for adaptation) 2. Emotions are adaptive psychological mechanisms that signal "fitness affordances" in the social landscape. Emotions guide the person towards goals that would have conferred fitness in ancestral environments or avoided conditions that minimized fitness. 3. "Manipulation hypothesis" - emotions are designed to exploit the psychological mechanisms of other people ## Footnote All of these perspectives depend on the concept that emotions are universal and universally recognized the same way.

Question 60

# Evolutionary Psychology Empathy facilitates [answer], which offered an evolutionary [answer] for humans.

Answer 60

Empathy facilitates cooperation, which offered an evolutionary advantage for humans.

Question 61

# Evolutionary Psychology Propensity to [answer] is a negative universal trait in humans. | Remember the gene

Answer 61

Propensity to aggression is a negative universal trait in humans. Gene - ADRA2C