Question 1

People who are genetically unrelated but are raised in the same home have IQ scores that are more similar than those of genetically unrelated people raised in different homes.

Accepted Answer

This phenomenon is known as the "shared environmental effect" on IQ scores. It suggests that the environment in which individuals are raised (such as their family's socioeconomic status, parenting style, education level, and access to resources) can have an impact on their cognitive development and performance on IQ tests. However, it is important to note that genetics also play a significant role in IQ scores, and the influence of environmental factors may decrease as individuals age and become more independent from their family context.

Question 2

Heritability refers to the percentage of variation, within a given population, that is due to heredity.

Accepted Answer

Heritability is the extent to which individual differences in traits are due to genetic variation within a population. It is typically expressed as a percentage ranging from 0% to 100%, where 0% means that the trait is entirely due to environmental factors, and 100% means that it is entirely due to genetic factors. Therefore, the statement is true.

Question 3

Heritability estimates can be applied to differences within groups but not to differences between groups, because each group experiences different environmental factors.

Accepted Answer

Heritability estimates can only apply to differences within groups because differences between groups can be influenced by different environmental factors, making it difficult to isolate the genetic factors.

Question 4

Environmental factors influence which of the many genes we inherit are actually switched on, or activated. Both heredity and environment are important in determining intelligence level.

Accepted Answer

Both heredity and environment are important in determining intelligence level since environmental factors can affect gene expression and therefore contribute to an individual's intelligence in addition to genetic factors.

Question 5

The intelligence of fraternal twins raised in the same home is more similar than the intelligence of nontwin siblings raised in the same home. This finding provides evidence for the effects of environment on intelligence because fraternal twins and other siblings have the same degree of genetic relatedness.

Accepted Answer

Fraternal twins share the same environment but only about 50% of their genes, while nontwin siblings share about 50% of their genes but may have different environments due to birth order, age spacing, and other factors. Therefore, the fact that fraternal twins have more similar intelligence than nontwin siblings suggests that shared environment plays a role in intelligence, beyond genetic factors.

Question 6

Only data from identical twins are used to produce heritability estimates of intelligence and other characteristics, since other relatives, such as siblings, are too genetically different to produce usable data.

Accepted Answer

Heritability estimates of intelligence and other characteristics are often derived from studies involving both identical twins and other relatives, such as fraternal twins and siblings, to compare genetic similarities and differences.

Question 7

Evidence for the importance of the environment in determining IQ scores derives from the improvement in average IQ scores that occurred in several cultures and countries during the past few generations. This phenomenon is called the Flynn effect.

Accepted Answer

The statement is true as the Flynn effect is a well-documented phenomenon that refers to the increase in average IQ scores observed in several cultures and countries over the past few decades, which is thought to be linked to improvements in environmental factors such as education, nutrition, and healthcare.

Question 8

A heritability estimate of 60 percent for intelligence would mean that roughly 60 percent of a given individual's IQ score is due to his or her genes.

Accepted Answer

Heritability estimates refer to the proportion of variation in a trait within a population that can be attributed to genetic differences, not the proportion of an individual's trait due to genes.

Question 9

A new approach to autistic spectrum disorders called neurodiversity involves the recognition that people with autistic spectrum symptoms process information, communicate, and experience their social and physical environments differently than neurotypical people, who don't have autistic symptoms.

Accepted Answer

The statement correctly describes the approach of neurodiversity to autistic spectrum disorders.

Question 10

A worldwide survey of intelligence test scores showed significant gains in average IQ scores in 14 nations in just one generation. These results provide support for environmental influences on IQ scores because the amount of time involved is far too short for genetically influenced changes to have occurred.

Accepted Answer

The statement accurately reflects the evidence presented in the survey, which suggests that environmental factors are responsible for the increase in IQ scores observed in just one generation. Genetic changes would require a much longer time frame to occur, so the rapid changes seen in some nations are more likely due to changes in education, nutrition, and other environmental factors that affect cognitive development.

Question 11

Identical twins share exactly the same genes because they developed from a single fertilized egg that split into two.

Accepted Answer

Identical twins are formed when a single fertilized egg splits into two, resulting in two genetically identical individuals. Therefore, they share exactly the same genes.

Question 12

The Flynn effect provides support for the influence of the environment in determining IQ scores.

Accepted Answer

The Flynn effect refers to the observation that IQ scores of the population have been increasing over time, which suggests an influence of environmental factors (such as improvements in education, technology, and nutrition) on intelligence.

Question 13

The fact that IQ scores have remained relatively stable in the United States and 14 other nations since World War II, despite improvements in nutrition and education, is evidence that supports the idea that intelligence is primarily due to genetics.

Accepted Answer

IQ scores have actually increased over time, a phenomenon known as the Flynn effect, suggesting that environmental factors like education and nutrition significantly influence intelligence.

Question 14

In terms of intelligence, identical twins reared together have very similar scores, whereas fraternal twins reared together have IQ scores that are less similar.

Accepted Answer

This statement is true according to studies on twin intelligence. Since identical twins share 100% of their DNA, they are genetically identical, and therefore have very similar IQ scores. Fraternal twins share about 50% of their DNA, making them more similar than regular siblings but less similar than identical twins, and thus have less similar IQ scores.

Question 15

The Flynn effect provides support for the influence of genes in determining IQ scores.

Accepted Answer

The Flynn effect refers to the phenomenon of average IQ scores increasing over time, which is attributed to environmental factors such as improved nutrition and education. While genetics may play a role in individual IQ, the Flynn effect is not evidence for genetic influence on IQ scores.

Question 16

Howard Gardner used the "two pots" analogy to help explain the relationship between cultural values, the development of agriculture, and the evolution of linguistic and analytical intelligence.

Accepted Answer

Howard Gardner is known for his theory of multiple intelligences, not for using the "two pots" analogy related to cultural values, agriculture, and intelligence evolution.

Question 17

Psychologists generally agree that both genes and environmental factors contribute to intelligence.

Accepted Answer

Psychologists have found that factors such as educational opportunities, nutrition, and upbringing can impact a person's intelligence while genes are also considered to play a role. Most agree that intelligence is influenced by a complex interplay of both genetic and environmental factors.

Question 18

Stereotype threat refers to the phenomenon that occurs when members of a group are aware of a negative stereotype about the group and fear that they will be judged in terms of that stereotype.

Accepted Answer

This is the definition of stereotype threat.

Question 19

It is now known that environmental factors influence or regulate the activation of many of the genes that we inherited from our biological parents.

Accepted Answer

Environmental factors such as diet, lifestyle, and exposure to toxins or pollutants can affect the way genes are expressed or activated. This field of research is known as epigenetics, and it has led to a greater understanding of the complex interactions between nature and nurture in shaping human development and health.

Question 20

Many psychologists today believe that the worldwide decline in IQ scores is the result of environmental pollution and inadequate nutrition.

Accepted Answer

The answer of Many psychologists today believe that the worldwide...

Quiz 7: Thinking, Language, and Intelligence