Chapter 4 - Nature vs. Nurture

Question 1

What is behavior genetics?

Answer 1

The study of how heredity and the environment can contribute to human differences.

Question 2

What are genes?

Answer 2

Part of DNA molecules, found in chromosomes in the nuclei of cells.

Humans have 46 chromosomes in 23 pairs - half from the mother and half from the father.

Genes are not blueprints, they are molecules that direct the assembly of proteins that build the body. This genetic protein assembly can be turned on and off by the environment or other genes.

Any trait we see is a result of the complex interactions of many genes and countless other molecules.

Question 3

What do behavior geneticists hope to do in the future?

Answer 3

Control variables. Can we design experiments to keep genes constant and vary the environment to see what happens? Or vary the genes in the same environment?

Question 4

Discuss fraternal and identical twins.

Answer 4

Fraternal twins from separate eggs are no more genetically alike than other siblings.

Studies of twins in adulthood show that identical twins are more alike than fraternal twins in: personality traits such as extraversion and neuroticism, behaviors and outcomes such as divorce rate, and abilities such as overall intelligence test scores.

We can study the traits of identical twins as they grow up or if they were raised separately. Ex. Minnesota Twin Studies - identical twins that were raised in separate homes with different cultures and parenting styles still had very similar personalities, thinking styles, fears, attitudes, interests, intelligence, brain waves, and heart rate.

Question 5

Are adopted children more similar to their adopted or their biological relatives?

Answer 5

Studies have been performed with adopted children for whom the biological relatives are known and adoptive children seem to be more similar to genetic relative than their environmental / nurture relatives.

Question 6

Notes about parenting and differences in siblings.

Answer 6

Parenting influences things like religious and political beliefs, values, manners, attitudes, and habits.

Why are siblings so different?
Siblings only share half their genes. Genetic differences become amplified as people react to them differently. Families are slightly different to each child - the youngest has more older siblings and older, wiser, more tired parents.

Temperament is not caused by parenting. Most people do not see changes in temperament, or the general level and style of emotional reactivity.

Question 7

What are the three general types of temperament?

Answer 7

Easy, difficult, and slow to warm up.

Question 8

What is molecular genetics?

Answer 8

The study of the molecular structure and function of genes.

How do specific genes have an influence on behaviors? Researchers study families who have had a disorder across several generations and compare differences in affected versus unaffected individuals.

Question 9

What is heritability?

Answer 9

The amount of variation in the population that is explained by genetic factors.

It does not tell us the proportion that genes contribute to the trait for any one person or what differences between groups is due to genes.

Ex. same upbringing and experiences but differences in shyness.

Question 10

Physical and mental abilities develop in response to?

Answer 10

Experience.

Genetic traits influence the social environment which in turn affects behavior.

Question 11

What is self-regulation? Give an example.

Answer 11

Genes turn each other on / off in response to environmental conditions.

Ex. shortened daylight triggers animals to change fur colors or to hibernate.

Question 12

What is epigenetics? Give an example.

Answer 12

The environment acts on the surface of genes to alter their activity.

Ex. obesity in adults can turn off weight regulation genes in offspring.

Ex. infant rats denied of their mother’s normal licking had more epigenetic molecules that block access to the “on” switch for developing the brain’s stress hormone receptors.

The trait of being adaptable is built into the human genome. We have minds which allow us to change our behaviors in response to the environment to a greater degree than other species and we can shape our environment.

Question 13

What is evolutionary psychology?

Answer 13

The study of how evolutionary principles help explain the origin and functions of the human mind, traits, and behaviors.

Question 14

What was Balyaev and Trut’s artificial selection experiment?

Answer 14

Balyaev and Trut selected the most gentle, friendly foxes from a population and made them reproduce. They were able to shape these aggressive creatures into domesticated foxes, just as wolves were once shaped into dogs.

Question 15

Why does stranger anxiety develop between the ages of 9 and 13 months?

Answer 15

Humans learn to walk around this time, and infants who use this new ability to walk away from their family and toward a lion might not have survived to produce unlike those who clung to their parents.

Question 16

What are some mating differences in males and females?

Answer 16

Generally men think more about sex and are more likely to think casual sex is acceptable.

Why might natural selection have resulted in greater male promiscuity?

Promiscuity in men promotes the continuation and spread of their genes, and there is little risk to doing this.

Promiscuity in females would not greatly increase the number of babies and has greater survival costs - childbirth can be dangerous.

Men seek women will fuller figures to make sure they’re not too young / old to have children. Women seek males with loyal behavior to ensure they stick around to provide for their children.

Question 17

What is the nature versus nurture debate?

Answer 17

How much of our personality / traits is inborn / determined by genes and how much do we get from our environment / peers / etc.

Question 18

What is growth and pruning?

Answer 18

At birth, we have more synapses than we need. Our brain decides which to keep through experiences. To make our well-used brain pathways work better, the unused connections are pruned away. If certain abilities are not used, they will fade.

Question 19

Is parenting a powerful environmental influence on development?

Answer 19

The power of parenting is clearest at the extremes - severe abuse and neglect.

Non-abusive “average” parents should ease off on the both blame and credit they assume for how their kids turn out.

Children of warm supportive parents feel better about themselves and are less hostile.

Question 20

What is the effect of peer influence on development?

Answer 20

Apparent conformity could be a selection effect - people are friends because they want to be with other like them. Ex. smoking.

Interaction with peers can teach new social skills.

Parents may indirectly select peers by selecting school and neighborhoods.

Question 21

What do parents influence and what do peers influence?

Answer 21

Parents influence education / career path, religious and political views, values, and self-discipline.

Peers influence cooperation skills, music, clothing, fun, good and bad habits, and popularity.

Question 22

What are some cultural influences on development?

Answer 22

Nature of culture - culture refers to the patterns of ideas, attitudes, values, lifestyle, habits, and traditions shared and passed on by a group of people.

Variation across culture - every culture has norms - standards for acceptable, expected behaviors. Ex. wearing shoes in house, greetings, etc.

Examples of changes in cultural variation over time - language changes in vocabulary and pronunciation, quickened pace of life, increased gender equality, less sleep, less in-person socialization, increased technology, people marry more for love and expect less romance.

There cultural changes happen too fast to be rooted in genetic change.

Culture shock - feeling lost about what behaviors are appropriate.

Question 23

What is an individualist culture?

Answer 23

A culture that values independence. These cultures promote personal ideals, strengths, goals, competition with other leading to individual achievement, and unique personal identity.

Question 24

What is a collectivist culture?

Answer 24

A culture that values interdependence. These cultures promote group and societal goals and duties, blending into a group, and identity and achievements are attributed to mutual support.

Question 25

What are some differences in child-rearing between individualist and collectivist cultures?

Answer 25

In individualist cultures parents might raise their children to be self-reliant and independent.

In collectivist cultures parents might raise their children to be compliant, obedient, and integrated into webs of mutual support.

People in Asia and Africa raise their children to be more emotionally and physically close to others then in western European cultures.

Question 26

IMPORTANT!!!!

Answer 26

Although there are cultural differences, the differences within any group are usually greater than differences between groups.

Differences in average blood pressure between groups may seem like a genetic difference but it may actually be a cultural differences attributed to differences in diet.

Question 27

What is gender development?

Answer 27

Gender refers to physical, social, and behavioral characteristics that are culturally associated with male and female roles and identity. Some traits may be genetic differences while others may be role differences.

Question 28

What are some biological differences in gender development?

Answer 28

Women enter puberty earlier, live longer, have more fat and less muscle, and are more likely to have anxiety and eating disorders.

Men are more likely to have autism, ADHD, and antisocial personality disorder - serial killers. They are also more likely to behave in ways that could physically harm others.

Question 29

What are some differences in social power between men and women?

Answer 29

In most societies men are socially dominant. Men often talk assertively and give their opinions. Women often express support and invite input.

When boys play they focus on the activity and have larger, more competitive groups with little intimate discussion.

When girls play they focus on the connection and conversation, have smaller, more social groups, and invite feedback.

Women communicate more than men and spend more time with friends, send more texts, and have longer phone calls. However, men and women speak about the same amount of words per day.

Men state opinions and solutions and talk more about things and actions.

Women seek input and explore relationships and talk about people and feelings.

Both men and women turn to women when they want someone to talk to and share worries and hurt.

When coping with their own stress women, more than men, turn to others for support - “tend and befriend.”

Question 30

What is the biology of gender?

Answer 30

Genetically, the only difference is a chromosome.

Female - XX
Male - XY

All embryos start the same and gender usually isn’t determined until about seven weeks in.

Question 31

What is a gender role?

Answer 31

Behaviors expected of people related to their identity as a man or woman.

Question 32

What is gender identity?

Answer 32

One’s sense of whether one if male or female and their sense of what it means to be that gender.

Question 33

What is the social learning theory?

Answer 33

Gender role behavior is learned through observation, imitation, rewards, and punishments.

Question 34

What are gender schemas?

Answer 34

The cognitive frameworks for organizing boy - girl characteristics.

Young children are internally motivated to categorize people and are motivated to conform.