assignment2

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Discuss two biologically based approaches to how personality might be inherited: behavioral genetics and evolutionary psychology.

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Personality traits that differ among individuals: not concerned with traits that are the same for everyone (e.g., need for food and water), but only in traits that vary across individuals

Examines how genes influence broad patterns of behavior (i.e., personality traits)

Eugenics: idea that humanity could be improved through selective breeding; and the less dramatic concern that people may think behavior is determined by genetics

Modern research is not concerned with these issues: Eugenics and cloning are not feasible; personality is determined by more than just genetics.

Activity: The Island

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Phenotype: observable traits

Genotype: genetic structure

Assumption: Traits and behaviors influenced by genes should be more similar among more closely related people

Heritability coefficient definition: percentage of the variance of a trait in the population that can be attributed to variance in genes

See Table 9.1 on p. 305

These are the average correlations across many traits when age and gender are controlled.

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Genes matter: Not all of personality comes from experience.

Shared family environment does not seem to matter very much: The average correlation of personality for adopted siblings is only .05.

Developmental psychology: aggression, love styles; including the development of psychopathology

Effects of parent training: influences behavior and emotional control

Based on behavior: affects aggression and personality measured with direct observation

Activity: Identical Twins, Raised Apart

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Discussion question

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Molecular genetics definition: determine whether differences in traits are correlated with differences in a particular gene

Alleles: variants of a gene; different alleles can be associated with different outcomes (anxiety, reaction to stress, amygdala response to fearful and unpleasant stimuli); prevalence may vary across cultural groups, but many genes are involved in complex traits

Cultural difference: the allele that is related to neurotic responding is more common in some cultures (Japanese) than others (Caucasian)

Limitations: Many genes are probably involved in complex traits.

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Genes are not causal; they only provide the design.

Environments can affect heritabilities: Nutrition and height (heritability will be higher when all children have the same level of nutrition, but lower when nutrition differs and therefore contributes differently to height); likewise for the relationship between intellectual stimulation and educational opportunities and IQ

Genetic expression and social environment: height and teasing

Choice of environments: people tend to choose or create environments compatible with genetically influenced tendencies

People can react differently to the same environment: people with a short allele for the 5-HTT gene were more likely to have depression after a stressful experience than those with the long allele, but there was no difference in depression for those who didn’t have a stressful experience; however, this is not found in every study.

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Epigenetics: nongenetic influences on a gene’s expression (stress, nutrition); experience, especially early in life, can influence how or whether a gene is expressed during development; most research has been with rats (stress response differs as a function of early maternal care)

The big picture will be complicated because traits will be associated with many genes, with effects that depend both on other genes and on the environment.

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Apply evolutionary theory to human behavior

Assumption: Behavioral patterns developed because they were necessary for survival in evolutionary history; characteristics with more survival value are more likely to appear in subsequent generations.

Aggression: increase protection, can lead to dominance in a social group and higher status; but also has negative outcomes such as fighting and war

Altruism: may increase inclusive fitness by helping and protecting others

Self-esteem: reflection of degree of acceptance by others; sociometer theory

Depression: pain signals something is wrong and must be fixed; crying may be a way of seeking social support; fatigue and pessimism may prevent wasting resources

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Mate selection definition: what one looks for in the opposite sex

Mating strategies definition: how one handles heterosexual relationships

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Both want the highest likelihood of healthy offspring who will survive and reproduce: difference is in how this goal is pursued and achieved; female attractiveness signals youth and physical health and ability to have children; males need to provide economic resources and appropriate attitudes to support a family

Attraction is influenced by more than physical characteristics: liking, perceptions of honesty

Culture matters: sex differences in mate preferences are smaller in countries with smaller gender gaps in earning and opportunities

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Mating strategies: how one establishes and maintains heterosexual relationships

Differences between men and women: desired number of sexual partners, faithfulness to partner, selectivity of partners; explained by differences in factors that affect reproductive success

Explained in terms of reproductive success: men—having as many children as possible and not wasting time taking care of children who are not their own; women—finding a man to help support them and the children

Some similarities: maintaining a stable relationship

Activity: Gender Differences in Mate Selection

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Sociosexuality definition: willingness to engage in sexual relations in the absence of a serious relationship

High levels (less restricted): especially interested in physical attractiveness and social visibility of potential partners

Low levels (more restricted): more interested in personal qualities and potential to be good parents

Men with higher levels knew their own mate value more accurately (assumption that this is an important skill for someone who wants to have sexual relations with many women), and were chosen to get to know better by more women; but this was not the case for women

Try For Yourself 9.1 on pp. 327–328: The Sociosexuality Scale

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Gender difference: Men report they would be more upset at sexual infidelity and women at emotional infidelity (although 55% of men think they would be more upset by imagining their partner falling love with someone else than by imagining their partner in different sexual positions with someone else, versus 88% of females).

Explained by differences in factors that affect reproductive success: men—having as many children as possible and not wasting time taking care of children who are not their own; women—finding a man to help support them and the children

Sexy son hypothesis: explains an alternative mating strategy for women; mating with an attractive but unstable male will produce sexier sons who will be more likely to reproduce

Diversity is necessary for viability: different traits and behaviors are adaptive in different situations (neuroticism and anxiety in dangerous versus safe situations; openness to experience with illegal drugs versus types of exercise)

Behavioral patterns evolve as reactions to particular environmental experiences, so different environments will result in different behavioral patterns (traits)

Several possible behavioral strategies may have evolved: Each individual uses the strategy that makes the most sense given other characteristics.

Some behaviors may be frequency dependent: They adjust according to how common they are (some behaviors are adaptive as long as only a few people do them; examples include psychopaths and con artists).

Human nature is flexible: This undermines the idea of evolution, which makes evolutionary theory controversial.

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Methodology: It doesn’t really make sense to think of an instinctual basis for rare behaviors (rape, stepchild abuse). It is probably not wise to think that every trait or behavior pattern has an adaptive advantage; some may be side effects of other adaptive behaviors.

Responses: Alternative explanations are always possible in any area; specific predictions can be tested.

Reproductive instinct: Not everyone wants as many children as possible.

Conservatism: implies that the current behavioral order was inevitable and is unchangeable and appropriate (including male promiscuity and aggressive tendencies)

Responses: This is scientifically irrelevant; just because something is natural does not mean it is good.

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Human flexibility: People are more flexible than evolution and genetically determined behavior account for.

Response: acknowledges that we are evolved to behave flexibly and we can overcome innate urges

Biological determinism or social structure: Sex differences may be caused by social structure.

Aspects of social structure: Men tend to be warriors, rulers, and controllers of economic resources; women tend to stay near the home (to bear and raise children); this can be used to explain differences in mate preferences.

Theoretical importance: how much human nature is determined by evolution and biology versus the effects of society

Practical importance: The world is changing, and therefore sex differences may also change.

Activity: Be an Evolutionary Psychologist

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Figure 9.6 on p. 339

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Biological reductionism definition: Everything about the mind can be reduced to biology.

Important psychological questions: What are people thinking? How are people influenced by the environment, including other people?

Activity: Identity Shift

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Correct answer: c

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Correct answer: a

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Correct answer: d

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