Chapter Six

Question 1

heritability

Answer 1

the proportion of observed variance in a group of individuals that can be accounted for genetic variance

Question 2

three common misconceptions of heritability

Answer 2

• it can be applied to a single individual
• it is constant
• it is an absolutely precise statistic

Question 3

environmentality

Answer 3

the % of observed variance in a group of individuals that can be attributed to environmental differences

Question 4

family studies

Answer 4

correlate the degree of genetic relatedness among family members with the degree of personality similarity
(if a personality characteristic is highly heritable, then the family members with greater genetic relatedness should be more similar to each other)

Question 5

twin studies

Answer 5

estimate heritability by gauging whether identical twins who share 100% of their genes are more similar than fraternal twins who share 50% of their genes
(studies have shown identical twins are more similar than fraternal in dominance, height, etc. suggesting heritability plays a causal role in influencing the differences)

Question 6

equal environments assumption

Answer 6

assumes that environments experienced by identical twins are no more similar to each other than are the environments experienced by fraternal twins

Question 7

adoption studies

Answer 7

examines the correlations between adopted children and their adoptive parents

Question 8

representativeness assumption

Answer 8

assume that adopted children, their birth parents, and their adoptive parents are representative of the general population
(ie. that adoptive parents are no more different than parents who do not adopt)

Question 9

selective placement

Answer 9

potential problem referring to if adopted children are placed with adoptive parents who are similar to their birth parents, then this may inflate the correlations between the adopted children and their adoptive parents

Question 10

heritability estimates for extraversion and neuroticism

Answer 10

0.60, 0.54

Question 11

heritability estimates for temperaments

Answer 11

0.50

Question 12

heritability estimates for psychopathic personality traits

Answer 12

moderate to high heritability

Question 13

heritability estimates for big five traits

Answer 13

0.48

Question 14

heritability estimates for attitudes and preferences

Answer 14

moderate heritability

Question 15

heritability estimates for religious attitudes

Answer 15

essentially 0.00
(increases with age)

Question 16

tendency to smoke or abuse alcohol heritability?

Answer 16

there is evidence of heritability

Question 17

heritability estimates for alcoholism

Answer 17

0.50+

Question 18

heritability estimates for natural tendency of marriage

Answer 18

0.68

Question 19

shared environments example

Answer 19

brothers and sisters in the same family, some features of their environment are shared: the number of books in the home; the presence or absence of a TV, video game console, or computer

Question 20

non-shared environments

Answer 20

the same brothers and sisters do not share all features of their environment: some might get special treatment from their parents, they might have different groups of friends, rooms in the house. One might go to summer camp, whereas the others stay home each summer.