Chapter 2&4

Question 1

Is nature/nurture responsible for human behavior?

Answer 1

1. Almost all behavior is heritable to some degree
   2.Genes do not operate in isolation from the environment. Throughout the life span, the environment shapes how our genes are expressed, and our genes also shape our environments

Question 2

Gene expression

Answer 2

What genes do is make proteins that in turn make the body and brain work. Some of these proteins switch other genes on and off

Question 3

Psychological disorders are polygenic

Answer 3

meaning that the influence of several genes, perhaps operating at different times during development, turning themselves on and off as they interact with a person’s environment, is the essence of genetic vulnerability

Question 4

Do we inherit psychological disorders from our genes alone?

Answer 4

No we develop them through the interaction of our genes with our environments

Question 5

Heritability

Answer 5

Heritability refers to the extent to
which variability in a particular behavior (or disorder) in a population can be accounted for by
genetic influences.

Question 6

There are two important points about heritability to keep in mind:

Answer 6

1. Heritability estimates range from 0.0 to 1.0: the higher the number the greater the heritability
2. Heritability is relevant ONLY for a large population of peo
   ple, not a particular individual. Thus, it is incorrect to talk
   about any one person’s heritability for a particular behavior
   or disorder. Knowing that the heritability of attention-deficit/
   hyperactivity disorder (ADHD) is around 0.70 does not mean
   that 70% of Jane’s ADHD is the product of her genes and 30%
   other influences. Rather, it means that in a population (e.g.,
   a large sample in a study), the variation in ADHD is under
   stood as being attributed to 70% genetic influences and 30%
   environmental influences. There is no heritability of ADHD
   (or any disorder) for a particular individual.

Question 7

Shared environment

Answer 7

factors include those things that members of a family have in common, such as family income level, child-rearing practices, and parents’ marital status and quality.

Question 8

Nonshared environment

Answer 8

factors are those things believed to be distinct among members of a family, such as relationships with friends or specific events unique to a person (e.g., being in a car accident or on the swim team), and these are believed to be important in understanding why two siblings from the same family can be so different

Question 9

Behavior genetics

Answer 9

Is the study of the degree to which genes and environmental factors influence behavior. Note that behavior genetics is not the study of how genes or the environment
determines behavior. Many behavior genetics studies estimate the heritability of a psychological
disorder without providing any information about how the genes might work

Question 10

Genotype

Answer 10

The total genetic makeup of an individual, consisting of inherited genes, is referred to as the

Question 11

Phenotype

Answer 11

The phenotype is the product of an interaction between the genotype and the environment. For example, a person may be born with the capacity for high intellectual achievement, but whether he or she develops this genetically given potential depends on environmental influences such as upbringing and education.

Question 12

Is intelligence an index of phenotype or genotype?

Answer 12

Phenotype