Nature, Nurture, & Human Diversity Chapter 3

Behavioral Genetics How do behavior geneticists explain individual differences? –Behavior genetics: the study of the relative power and limits of genetic and environmental influences on behavior –Heredity interacts with our experience to create who we are –Every person shares 99.9% of their DNA, it’s the.1% that makes the difference

Twin & Adoption Studies Identical Twins are genetically IDENTICAL, fraternal twins are not. They are assumed to have shared that same conception, uterus, and cultural history (although we now know this may not be the case) Fraternal Twins are genetically the same as brothers and sisters. Studies have shown that identical twins are a lot more similar in terms of behavior than fraternal twins. Why may this be? Is it because they have the same genes or can there be more?

Separated Twins The book tells the story of Jim and Jim who were separated at birth and adopted by blue collar families. Years later they were reunited and were exactly the same. How much of it is genetic? Sometimes we are VERY similar to a stranger. W4jOMIhttp:// W4jOMI

Biological vs Adoptive Relatives Are adopted kids more like their birth parents or their adoptive parents? According to research conducted by behavioral geneticists, that people who grow up together do not resemble each other a lot in terms of personality. In other words, they claim that environmental factors do not have ANY influence on personality. However, parents can shape attitudes, values, manners, faith, and politics.

Temperament & Heredity Temperament: a person’s characteristic emotional reactivity and intensity. Babies differ in temperament Heredity may predispose different temperaments

Nature & Nurture Nature and Nurture work together like two hands clapping Genes and experience INTERACT, one is not more important than the other. –Example: Baby #1 is very cute, while Baby#2 is not. Baby#1 will get more attention and warmth allowing it to become a more social person and attract more friends than Baby#2. –People tend to respond differently to more attractive people. What are some examples? –Parents may also treat their children differently. One child elicits punishment, another does not.

Evolutionary Psychology How do evolutionary psychologists use natural selection to explain behavioral tendencies? –Evolutionary Psychology: the study of the evolution of behavior and the mind using principles of natural selection –Example 1: evolutionary psychologists explain men’s more recreational approach to sex by attributing it to their ability to “spread their genes” –Example 2: Men judge women as more likeable if they have a youthful appearance and smooth skin, because they are more likely to be fertile and healthy –Example 3: Women are more attracted to men who seem bold, youthful, dominant, and affluent because these attributions are related to greater protection –Nature selects behaviors that will allow for greater reproduction of our genes

Evolutionary Psychology and Gender Differences According to Evolutionary Psychologists: –Men desire sex more frequently, think more about sex, masturbate more, initiate more sex, and sacrifice more for sex. Do you agree or disagree? –Studies: In 2005, college students were given the following phrase: “if two people really like each other, it’s all right for them to have sex, even though they’ve only known each other for a very short time.” –58% of men and 34% of women agreed They were then given the following phrase: “I can imagine myself being comfortable enjoying casual sex.” –48% of men and 12% of women agreed In a study utilizing 18 to 59 year olds, 59% of women and 25% of men cited affection as the reason for first intercourse. Gay men report more interest in uncommitted sex than lesbian women. Why may this be so? Thoughts?

Critiquing the Evolutionary Perspective Starts with an effect and works backwards to find an explanation Doesn’t account for cultural differences or other possible explanations. –For instance, explains why men are not loyal, but fails to look at men who are loyal.

Parents & Peers To what extent are our lives shaped by parents and peers? –Parental experience: Our experience with parents begins in the womb. These experiences foster brain development. –As a society we credit parents with their children’s successes and blame them for their failures. –Parents can have great effects on achievement (mostly school or vocational related), but may not be very influential when it comes to personality. –How much blame or praise do you think parents deserve?

Peer Influences Preschoolers who refuse to eat a certain food will commonly eat it if placed in a table where the other children are eating it. Children who hear English with an accent at home and a different accent at school will eventually pick up the school accent. Teens who smoke typically have friends not parents who smoke. Parents may be more influential when it comes to education, values, politics, and religion, while peers may influence music, dress, style, etc.

Cultural Influences Culture: the enduring behaviors, ideas, attitudes, and traditions shared by a group of people which is transmitted from generation to generation. Each culture has its own norms (rules) Cultures can differ in terms of accepted personal space

Cultural Influences Individualism: giving priority of one’s own goals over that of the group. Identifying oneself in terms of personal attributions. –Western Society Collectivism: giving priority to the goals of one’s group (often the extended family)

Culture & Childrearing Do you prefer children who are independent or children who comply with what others think? –Western Culture: “You are responsible for yourself”. “Be true to yourself. Follow your conscience. Discover your gifts. Think about your needs.” –Collectivistic Culture: “Be true to your traditions. Be loyal to your heritage and culture. Show respect to your parents and elders.” –Which one are you?

Cultural Differences in Childrearing Many Asians and Africans live in cultures that value emotional closeness. Thus, children commonly sleep with their parents. Upper-class British families traditionally handed of routine care giving to nannies and sent their children to boarding school at about age 10. The African Gusii, carry their children on their backs, without little face-to-face interaction. Once the mother becomes pregnant, the toddler is weaned off and handed to an older sibling or someone else. What are some other cultural differences in child rearing that you have noted?

Gender Development Gender Similarities and Differences: –Men and women are similar in some aspects and different in others For example: Women have less muscle and more fat, and start puberty earlier. Men admit to more aggression than women. Although aggression may be expressed differently for women. Men are perceived as more dominant Men and women bond in different ways Gender roles: our expectations about the way men and women should behave