Question 1

An estimate of the proportion of trait variability in a population that is determined by variations in genetic inheritance is known as a(n)
A)heritability ratio.
B)percentile score.
C)intelligence quotient.
D)reaction range.

Accepted Answer

Heritability ratio is the correct term for estimating the proportion of trait variability in a population that is determined by genetic inheritance. This concept is often used in genetics and psychology to understand how much of a particular trait, such as intelligence or height, can be attributed to genetic factors versus environmental factors.

Question 2

Researchers who believe that IQ is largely genetic argue that the heritability of IQ is close to ​
A)100%.
B)80%.
C)60%.
D)50%.

Accepted Answer

Researchers who argue that IQ is largely genetic often cite heritability estimates around 80%, though estimates can vary based on the study and population.

Question 3

Evidence for the role of environmental influences on intelligence is provided by studies that compare ​
A)adopted children to their biological parents.
B)adopted children to their adoptive parents.
C)children reared by their biological parents to their biological parents.
D)identical twins reared together and fraternal twins reared together.

Accepted Answer

Studies comparing adopted children to their adoptive parents show how environmental factors (such as home environment, education, and socio-economic status) can influence the development of intelligence, providing evidence for the role of environmental influences.

Question 4

The BEST evidence supporting the role of genetic factors in intelligence is provided by studies that compare ​
A)children to both their biological and adoptive parents.
B)identical and fraternal twins.
C)people born in different generations since the 1930s.
D)children raised in poverty and middle-class children.

Accepted Answer

Studies comparing identical and fraternal twins are the best evidence for the role of genetic factors in intelligence because identical twins share 100% of their genes, while fraternal twins share about 50%, similar to regular siblings. This allows researchers to isolate the effects of genetics from environmental factors by comparing the similarities in intelligence between the two types of twins.

Question 5

If environment affects intelligence, you should predict that the IQs of children who stay in understaffed orphanages will
A)gradually decline as they grow older.
B)show normal increases with development.
C)start out low but gradually increase as they reach puberty.
D)be fairly normal until they reach puberty, when there will be a sharp decline.

Accepted Answer

Children in understaffed orphanages often lack the necessary stimulation and interaction required for optimal cognitive development. This can lead to a gradual decline in IQ as they grow older due to the absence of enriching environments that foster learning and mental growth.

Question 6

If the differences in IQ scores among people were entirely a result of genetic factors, you would expect to find that the correlation in IQ scores would be ​
A)higher for fraternal twins reared together than for identical twins reared apart.
B)higher for identical twins reared together than for identical twins reared apart.
C)the same for identical twins reared together and for identical twins reared apart.
D)lower for identical twins reared together than for identical twins reared apart.

Accepted Answer

If the differences in IQ scores were entirely due to genetic factors, the environment would have no effect on these scores. Therefore, identical twins (who share 100% of their genes) would have the same correlation in IQ scores regardless of whether they were reared together or apart, as their IQs would be influenced solely by their genetics.

Question 7

The heritability ratio for IQ would be LOWEST among which of the following groups?
A)Young children living in poverty
B)Older adults living in poverty.
C)Young children from wealthy families.
D)Older adults from wealthy families.

Accepted Answer

The heritability ratio for IQ is lowest among young children living in poverty because environmental factors, such as access to nutrition, educational resources, and stimulation, play a larger role in their cognitive development compared to genetic factors. In contrast, in more affluent environments where these resources are abundant, genetic factors tend to have a greater influence on IQ.

Question 8

In which of the following cases is the correlation between IQ scores the HIGHEST?
A)Identical twins reared apart
B)Siblings reared apart
C)Fraternal twins reared together
D)Adoptive siblings reared together

Accepted Answer

Identical twins, even when reared apart, tend to have more similar IQ scores than any other group due to their genetic identity.

Question 9

Most explanations for the Flynn effect revolve around ​
A)genetic influences on IQ.
B)group differences in basic intelligence.
C)changes in testing procedures.
D)a variety of environmental factors.

Accepted Answer

The Flynn effect, which refers to the observed rise in average IQ scores over time, is primarily attributed to environmental factors such as improvements in nutrition, education, and health rather than genetic influences, group differences in intelligence, or changes in testing procedures.

Question 10

The fact that the correlation in IQ scores between identical twins reared apart is higher than that between fraternal twins reared together suggests that intellectual development is ​
A)influenced more by environmental factors than by genetics.
B)affected equally by genetics and environmental factors.
C)influenced more by genetics than by environmental factors.
D)not affected by either genetics or environmental factors.

Accepted Answer

The higher correlation of IQ scores between identical twins (who share 100% of their genes) compared to fraternal twins (who share about 50% of their genes) even when reared apart indicates a significant genetic component to intellectual development. This suggests that genetics plays a more substantial role than environmental factors in intellectual development.

Question 11

Which of the following six-year-old children would be MOST likely to experience an increase in IQ over the next few years? ​
A)Adam, who continues living in an understaffed orphanage
B)Brenda, who recently started living in an understaffed orphanage following the death of her parents
C)Cathy, who was recently adopted from an understaffed orphanage by loving middle-class parents
D)David, who continues living with his loving middle-class parents

Accepted Answer

Cathy is most likely to experience an increase in IQ because moving from an understaffed orphanage to a nurturing environment provided by loving middle-class parents can significantly improve cognitive development and stimulate intellectual growth.

Question 12

Experts estimate that the heritability of intelligence is approximately 50%. This suggests that ​
A)50% of a person's intelligence is due to genetic inheritance. ​
B)50% of a person's intelligence is due to environmental factors.
C)50% of the variability in intelligence in a population of individuals is due to variations in genetic inheritance.
D)50% of the difference in average intelligence test scores between different ethnic groups is due to genetic inheritance.

Accepted Answer

Heritability estimates, like the 50% figure for intelligence, refer to the proportion of variation in a trait (in this case, intelligence) within a population that can be attributed to genetic differences among individuals, not the proportion of an individual's trait that is due to genetics or environment.

Question 13

Adoption studies provide support for the influence of ​
A)environmental factors on intelligence.
B)genetic factors on intelligence.
C)neither environmental nor genetic factors on intelligence.
D)both environmental and genetic factors on intelligence.

Accepted Answer

Adoption studies support the influence of both environmental and genetic factors on intelligence by showing that adopted children can share traits with both their biological parents (genetic influence) and adoptive parents (environmental influence).

Question 14

The fact that the correlation in IQ scores between identical twins reared apart is lower than that between identical twins reared together suggests that
A)environmental factors can have an influence on intellectual development.
B)environmental factors have little impact on intellectual development.
C)genetic factors have no impact on intellectual development.
D)identical twins often do not have the same genotype.

Accepted Answer

The lower correlation in IQ scores between identical twins reared apart compared to those reared together indicates that differences in their environments can influence their intellectual development, suggesting the impact of environmental factors.

Question 15

The consensus among most researchers is that the heritability of intelligence is
A)close to 100%.
B)approximately 80%.
C)around 50%.
D)less than 40%.

Accepted Answer

The consensus among most researchers is that the heritability of intelligence is around 50%, indicating that both genetic and environmental factors play significant roles in determining intelligence.

Question 16

The Flynn effect is the finding that ​
A)performance on IQ tests seems to be rising steadily and consistently over time.
B)performance on IQ tests seems to be declining steadily and consistently over time.
C)fluid intelligence declines with age, while crystallized intelligence increases with age.
D)IQ scores tend to remain relatively stable after the age of seven.

Accepted Answer

The Flynn effect refers to the observed phenomenon that IQ test scores have been increasing steadily over time across the world. This suggests that average levels of intelligence, as measured by these tests, have been rising.

Question 17

The average IQ of this year's graduating class at Bradbury High is 112 points. The average IQ of the graduating class from 25 years ago was 107 points, and the average IQ of the graduating class from 50 years ago was 101 points. This trend is consistent with ​
A)heritability. ​
B)shifts in reaction range.
C)the Flynn effect.
D)reciprocal determinism.

Accepted Answer

The trend of increasing average IQ scores over time is consistent with the Flynn effect, which observes that IQ scores have been increasing worldwide for the past several decades.

Question 18

Which of the following statements about the heritability of intelligence is LEAST consistent with the research evidence? ​
A)Intelligence is partly inherited.
B)Intelligence is correlated with brain volume.
C)Specific genes account for most intelligent behavior.
D)Heritability ratios can fluctuate over the life span.

Accepted Answer

Research indicates that intelligence is influenced by many genes, each contributing a small effect, rather than specific genes accounting for most intelligent behavior. Intelligence is indeed partly inherited, correlated with brain volume, and its heritability can fluctuate over time, making option C the least consistent with current evidence.

Question 19

The IQ scores of children raised in substandard environments tend ​
A)to increase as the child gets older.
B)to change very little as the child gets older.
C)to decrease only after the child reaches adulthood.
D)to decrease as the child gets older.

Accepted Answer

Children raised in substandard environments often experience a decrease in IQ scores as they get older due to lack of stimulation, resources, and opportunities for cognitive development.

Question 20

Adoption studies comparing the intelligence of adopted children to their ______ provides support for the role of genetic factors in intelligence.
A)biological parents
B)adoptive parents
C)adopted siblings
D)adopted twins

Accepted Answer

Adoption studies often compare the intelligence of adopted children to their biological parents to understand the influence of genetics on intelligence. These studies typically find that the intelligence of adopted children is more similar to their biological parents than to their adoptive parents, suggesting a significant genetic component to intelligence.

Quiz 8: Cognition and Intelligence

An estimate of the proportion of trait variability in a population that is determined by variations in genetic inheritance is known as a(n)

Researchers who believe that IQ is largely genetic argue that the heritability of IQ is close to ​

Evidence for the role of environmental influences on intelligence is provided by studies that compare ​

The BEST evidence supporting the role of genetic factors in intelligence is provided by studies that compare ​

If environment affects intelligence, you should predict that the IQs of children who stay in understaffed orphanages will

If the differences in IQ scores among people were entirely a result of genetic factors, you would expect to find that the correlation in IQ scores would be ​

The heritability ratio for IQ would be LOWEST among which of the following groups?

In which of the following cases is the correlation between IQ scores the HIGHEST?

Most explanations for the Flynn effect revolve around ​

The fact that the correlation in IQ scores between identical twins reared apart is higher than that between fraternal twins reared together suggests that intellectual development is ​

Which of the following six-year-old children would be MOST likely to experience an increase in IQ over the next few years? ​

Experts estimate that the heritability of intelligence is approximately 50%. This suggests that ​

Adoption studies provide support for the influence of ​

The fact that the correlation in IQ scores between identical twins reared apart is lower than that between identical twins reared together suggests that

The consensus among most researchers is that the heritability of intelligence is

The Flynn effect is the finding that ​

The average IQ of this year's graduating class at Bradbury High is 112 points. The average IQ of the graduating class from 25 years ago was 107 points, and the average IQ of the graduating class from 50 years ago was 101 points. This trend is consistent with ​

Which of the following statements about the heritability of intelligence is LEAST consistent with the research evidence? ​

The IQ scores of children raised in substandard environments tend ​

Adoption studies comparing the intelligence of adopted children to their ______ provides support for the role of genetic factors in intelligence.

Researchers who believe that IQ is largely genetic argue that the heritability of IQ is close to

Evidence for the role of environmental influences on intelligence is provided by studies that compare

The BEST evidence supporting the role of genetic factors in intelligence is provided by studies that compare

If the differences in IQ scores among people were entirely a result of genetic factors, you would expect to find that the correlation in IQ scores would be

Most explanations for the Flynn effect revolve around

The fact that the correlation in IQ scores between identical twins reared apart is higher than that between fraternal twins reared together suggests that intellectual development is

Which of the following six-year-old children would be MOST likely to experience an increase in IQ over the next few years?

Experts estimate that the heritability of intelligence is approximately 50%. This suggests that

Adoption studies provide support for the influence of

The Flynn effect is the finding that

The average IQ of this year's graduating class at Bradbury High is 112 points. The average IQ of the graduating class from 25 years ago was 107 points, and the average IQ of the graduating class from 50 years ago was 101 points. This trend is consistent with

Which of the following statements about the heritability of intelligence is LEAST consistent with the research evidence?

The IQ scores of children raised in substandard environments tend