Question 1

Which of the following attributes seems to have the lowest heritability coefficient?
A) phobias
B) alcoholism
C) extraversion
D) depression

Accepted Answer

Phobias tend to have a lower heritability coefficient compared to alcoholism, extraversion, and depression. This suggests that environmental factors play a larger role in the development of phobias than genetic factors.

Question 2

Jacob and Ashley have the same father but have different mothers. About how much genetic material do they share?
A) 0
B) .125
C) .25
D) .50

Accepted Answer

Jacob and Ashley are half-siblings, sharing one parent (their father). Half-siblings typically share about 25% of their genetic material, which corresponds to choice C, .25.

Question 3

Monozygotic (MZ) twins share ________ percent of the genes that vary across individuals, and dizygotic (DZ) twins share, on average, ________ percent of the genes that vary across individuals.
A) 50; 25
B) 90; 10
C) 50; 100
D) 100; 50

Accepted Answer

Monozygotic (MZ) twins, also known as identical twins, originate from a single fertilized egg that splits into two, leading them to share 100% of their genes. Dizygotic (DZ) twins, or fraternal twins, come from two different eggs fertilized by two different sperm, sharing on average 50% of their genes, similar to any other pair of siblings.

Question 4

The notion that humans could be improved through selective breeding is called
A) eugenics.
B) cloning.
C) behavioral Darwinism.
D) heritability.

Accepted Answer

Eugenics is the belief or practice of improving the genetic quality of the human population, often by selective breeding.

Question 5

When personality psychologists measure trait differences in extraversion, what kinds of direct observations are they making?
A) phenotypic
B) genotypic
C) allelic
D) genome-wide

Accepted Answer

Personality psychologists measure trait differences in extraversion through phenotypic observations, which refer to observable characteristics or behaviors of individuals, rather than their genetic makeup (genotypic), specific alleles (allelic), or observations across the entire genome (genome-wide).

Question 6

What is the correct formula for calculating heritability? A) 2 (r_MZ - r_DZ) B) 2 - (r_MZ - r_DZ) C) 2 + (r_MZ -r_DZ) D) 2 (r_DZ - r_MZ)

Accepted Answer

The correct formula for calculating heritability is not represented by any of the provided options, as they all contain nonsensical or incorrectly formatted elements. Heritability is typically calculated using variance components, such as the variance due to genetics divided by the total variance.

Question 7

What might explain the difference in heritability coefficients between twin and non-twin studies?
A) increased measurement error in non-twin studies
B) the presence of interactive genetic effects
C) the greater statistical power of twin studies
D) the rarity of non-twin studies

Accepted Answer

The presence of interactive genetic effects can lead to differences in heritability coefficients between twin and non-twin studies, as twin studies can better account for these interactions due to the genetic similarities between twins.

Question 8

A scientist who studies how patterns of behavior characteristic of the entire human species originated because of the survival value they had for our ancestors is called a(n)
A) evolutionary psychologist.
B) behavioral geneticist.
C) heritability scientist.
D) behavioral Darwinist.

Accepted Answer

Evolutionary psychologists study how evolutionary principles such as natural selection have shaped behaviors in humans and animals. They explore how certain behavioral traits may have helped our ancestors survive and reproduce, thus becoming more prevalent in the population.

Question 9

Heritability estimates based on twin studies are likely ________, while heritability estimates based on broader family relationships are likely ________.
A) overestimated; underestimated
B) underestimated; overestimate
C) more accurate; less accurate
D) less accurate; more accurate

Accepted Answer

Heritability estimates based on twin studies might be overestimated because twins share a very similar environment in addition to their genetic similarities, which can inflate the perceived genetic influence. Estimates based on broader family relationships might be underestimated because they include a wider range of genetic sharing and environmental differences, making it harder to isolate the genetic contribution.

Question 10

Which of the following explanations is a correct statement regarding the shared genetic material between a mother and her child?
A) A mother only shares 25 percent of her genetic material with her child.
B) The shared genetic material between mother and child is higher for monozygotic twins relative to dizygotic twins.
C) A mother shares 50 percent of her genetic material with her child.
D) A mother shares 50 percent of the genetic material that varies across individuals.

Accepted Answer

The answer of Which of the following explanations is a...

Question 11

If the correlation between the shyness of a sample of dizygotic twin pairs is .25 and the correlation between the shyness of a sample of monozygotic twin pairs is .50, then the heritability coefficient for shyness is
A) .125.
B) .250.
C) .500.
D) 2.00.

Accepted Answer

The heritability coefficient is calculated as twice the difference between the monozygotic (MZ) and dizygotic (DZ) twin correlations. Here, it is 2 * (.50 - .25) = .50 or 50%.

Question 12

According to the text, biology will NEVER be able to explain
A) which brain structures are associated with depression.
B) how people act in their daily social environments.
C) how likely it is for schizophrenia to be passed down from mother to child.
D) the influence increased serotonin has on changes in behavior.

Accepted Answer

Biology focuses on the physiological and genetic aspects of organisms, including humans, but explaining how people act in their daily social environments involves complex interactions of culture, personal experiences, and societal norms, which extend beyond the scope of biological explanations.

Question 13

The presence of schizophrenia was measured in both monozygotic (MZ) and dizygotic (DZ) twins. The correlation between the MZ twins was .50 and the correlation between the DZ twins was .30. What is the heritability coefficient for schizophrenia?
A) .80
B) .20
C) .40
D) .65

Accepted Answer

The heritability coefficient for schizophrenia can be estimated using the formula 2(rmz - rdz), where rmz is the correlation for monozygotic twins and rdz is the correlation for dizygotic twins. Plugging in the given values, we get 2(.50 - .30) = .40.

Question 14

Behavioral genetics, like trait psychology, focuses on aspects of personality that ________, whereas evolutionary psychology more typically focuses on aspects of personality that ________.
A) all humans share; differ from one individual to another
B) vary among groups of individuals; vary among individuals
C) differ from one individual to another; all humans share
D) are species specific; are individual specific

Accepted Answer

Behavioral genetics and trait psychology focus on individual differences in personality traits, while evolutionary psychology emphasizes traits and behaviors that are common across all humans due to shared evolutionary history.

Question 15

If a trait is influenced by genes, then it ought to be more highly correlated across pairs of ________ than across pairs of ________.
A) genetic siblings; fraternal twins
B) fraternal twins; identical twins
C) identical twins; fraternal twins
D) adoptive siblings; genetic siblings

Accepted Answer

Identical twins share more of their genetic makeup than fraternal twins, so traits influenced by genes should be more similar between identical twins.

Question 16

The ________ refers to the underlying genetic structure that leads to the observable ________.
A) phenotype; genogram
B) genotype; phenotype
C) phenotype; genotype
D) genetic map; genetic architecture

Accepted Answer

The genotype refers to the genetic makeup of an organism, which leads to the phenotype, the observable characteristics or traits of that organism.

Question 17

The MOST controversial thing that has arisen from the study of behavioral genetics is that it has led to
A) ideas such as eugenics and cloning.
B) the chance that the public will think criminality is unchangeable.
C) heated debates between behavioral geneticists and evolutionary psychologists.
D) the chance that the public will think twins are the same in every way.

Accepted Answer

The study of behavioral genetics has historically led to controversial ideas like eugenics and cloning, which involve manipulating genetic traits and have significant ethical implications.

Question 18

According to estimates based on twin studies, the average heritability coefficient of many traits of personality is about ________ when using self-reports of personality.
A) .20
B) .40
C) .80
D) 1.0

Accepted Answer

The average heritability coefficient of many traits of personality, when using self-reports, is estimated to be about .40. This suggests that roughly 40% of the variation in personality traits among individuals can be attributed to genetic factors.

Question 19

The field of study that attempts to explain how individual differences in behavior (i.e., personality traits) are shared by biological relatives is called
A) evolutionary biology.
B) behavioral genetics.
C) heritability science.
D) behavioral Darwinism.

Accepted Answer

Behavioral genetics is the field that studies the role of genetic and environmental influences on behaviors, including how personality traits are passed down or shared among biological relatives.

Question 20

According to studies of non-twin relatives, the average heritability coefficient for most traits is about
A) .20.
B) .40.
C) .60.
D) .80.

Accepted Answer

The average heritability coefficient for most traits is about .20.

Quiz 9: Genetics and Evolution: the Inheritance of Personality

Which of the following attributes seems to have the lowest heritability coefficient?

Jacob and Ashley have the same father but have different mothers. About how much genetic material do they share?

Monozygotic (MZ) twins share percent of the genes that vary across individuals, and dizygotic (DZ) twins share, on average, percent of the genes that vary across individuals.

The notion that humans could be improved through selective breeding is called

When personality psychologists measure trait differences in extraversion, what kinds of direct observations are they making?

What is the correct formula for calculating heritability?

What might explain the difference in heritability coefficients between twin and non-twin studies?

A scientist who studies how patterns of behavior characteristic of the entire human species originated because of the survival value they had for our ancestors is called a(n)

Heritability estimates based on twin studies are likely , while heritability estimates based on broader family relationships are likely .

Which of the following explanations is a correct statement regarding the shared genetic material between a mother and her child?

If the correlation between the shyness of a sample of dizygotic twin pairs is .25 and the correlation between the shyness of a sample of monozygotic twin pairs is .50, then the heritability coefficient for shyness is

According to the text, biology will NEVER be able to explain

The presence of schizophrenia was measured in both monozygotic (MZ) and dizygotic (DZ) twins. The correlation between the MZ twins was .50 and the correlation between the DZ twins was .30. What is the heritability coefficient for schizophrenia?

Behavioral genetics, like trait psychology, focuses on aspects of personality that , whereas evolutionary psychology more typically focuses on aspects of personality that .

If a trait is influenced by genes, then it ought to be more highly correlated across pairs of than across pairs of .

The refers to the underlying genetic structure that leads to the observable .

The MOST controversial thing that has arisen from the study of behavioral genetics is that it has led to

According to estimates based on twin studies, the average heritability coefficient of many traits of personality is about ________ when using self-reports of personality.

The field of study that attempts to explain how individual differences in behavior (i.e., personality traits) are shared by biological relatives is called

According to studies of non-twin relatives, the average heritability coefficient for most traits is about