PSYC289 - Unit 9: Human Intelligence

What phrase did Sir Francis Galton coin to describe the heredity-environment issue?

Nature versus nurture.

Which two concepts related to statistics and testing were invented by Sir Francis Galton?

Correlation and percentile test scores.

What was the primary purpose of the Binet-Simon scale?

To determine a child's mental age, indicating the mental ability typical of a child of that chronological age.

How is an intelligence quotient (IQ) traditionally calculated?

Mental age divided by chronological age, multiplied by 100. (Lewis Terman)

Who published the WAIS intelligence test, the first high-quality IQ test for adults?

David Wechsler.

How did David Wechsler change the scoring scheme for IQ tests?

He discarded the intelligence quotient in favour of a scoring scheme based on the normal distribution.

What statistical procedure did Charles Spearman invent to identify clusters of related variables?

Factor analysis.

What does the 'g' factor represent in Charles Spearman's theory of intelligence?

General mental ability, which he believed all cognitive abilities share.

How does fluid intelligence differ from crystallized intelligence?

Fluid intelligence involves reasoning and problem-solving with novel information, while crystallized intelligence involves applying acquired knowledge and skills.

What are the three strata in John Carroll's model of intelligence?

Stratum I (g factor), Stratum II (eight broad abilities like Gf and Gc), and Stratum III (specific abilities like spelling).

What does factor analysis show?

it shows that different subtests of intelligence are positively correlated, suggesting a general intelligence factor (g), but individual performance is also influenced by specific abilities and other factors

What is the definition of a psychological test?

A standardized measure of a sample of a person's behavior.

What is an intelligence test?

A test that measures general mental ability.

What is the difference between aptitude tests and achievement tests?

Aptitude tests assess potential or specific types of mental abilities, while achievement tests gauge mastery and knowledge of specific subjects.

What is a personality test?

They measure various aspects of personality, including motives, interests, values, and attitudes

What is the purpose of standardization in psychological testing?

To ensure that a test is given, scored, and interpreted in a consistent and uniform way for all participants.

What is a standardization sample?

A representative group of people whose test scores are used to establish norms for a psychological test.

Why are test norms necessary in psychological testing?

Because performance on psychological tests is relative to how other people perform.

What is reliability in the context of psychological testing?

The consistency of a test's results.

What is test-retest reliability?

The extent to which a test produces similar results when given to the same people at two different times.

What is inter-rater reliability?

The consistency, agreement, and objectivity between two or more observers or raters assessing the same phenomenon.

What is a correlation coefficient?

A numerical index of the degree of relationship between two variables.

How is a correlation coefficient used to determine test reliability?

The closer the correlation coefficient comes to +1.00, the more reliable the test is.

What is the difference between a positive and negative correlation coefficient?

In a positive correlation, variables move in the same direction; in a negative correlation, they move in opposite directions.

What is validity in psychological testing?

The ability of a test to measure what it was designed to measure.

What is construct validity in the context of testing?

It refers to whether a test truly measures the theoretical concept it is intended to measure.

How is content validity defined?

It refers to whether a test covers all relevant aspects of the concept it is supposed to measure, providing a comprehensive and representative sample of the material.

What does criterion-related validity assess?

It assesses how well a test predicts or correlates with an external outcome, such as real-world performance or another established measure.

What is a normal distribution in the context of IQ testing?

A symmetric, bell-shaped curve representing how characteristics are dispersed in a population, where the mean, median, and mode for IQ are set at 100.

What is the standard deviation for IQ scores?

The standard deviation is 15.

What are deviation IQ scores?

Scores that locate subjects precisely within the normal distribution using the standard deviation as the unit of measurement.

What does a percentile score indicate?

The percentage of people who score at or below the score one has obtained.

What are raw scores in testing?

The original, unadjusted scores a person earns on a test before any conversion or interpretation.

How is intellectual disability characterized?

By significantly below-average intellectual functioning along with deficits in adaptive behavior, beginning in childhood.

What is the recommended IQ score threshold for determining intellectual disability?

An IQ score of 70 or below. Scoring two standard deviations or more below the mean are regarded as subnormal.

What percentage of the population is estimated to be intellectually disabled?

About 1 to 3 percent, with 1 percent being the closer estimate.

How is giftedness typically defined in terms of IQ?

Giftedness is typically defined as having an IQ score of 130 or higher. Scoring more than two or three standard deviations above the mean are regarded as gifted

What percentage of children are considered gifted?

About 2 to 3 percent.

How does heredity influence intelligence?

Heredity sets a range or potential for intelligence, and research shows that IQ is partly heritable.

What is the impact of schooling on IQ scores?

Schooling has a strong impact by developing and enhancing cognitive abilities; more years of schooling generally result in higher IQ scores.

What are the cultural factors of IQ?

Examples include socioeconomic status, nutrition and health, access to learning resources, cultural values around education and thinking styles.

Why can family studies be inconclusive regarding the source of intelligence?

Because family members share both genes and similar environments, making it impossible to determine if consistency in intelligence is due to genetics or shared environment.

Why are twin studies considered the best evidence for genetic influence on intelligence?

Because identical and fraternal twins normally develop under similar environmental conditions, allowing researchers to isolate genetic factors.

Why is the study of adopted children useful for psychological research?

It provides evidence regarding the relative effects of heredity and environment on human development.

What is a heritability ratio?

An estimate of the proportion of trait variability in a population that is determined by variations in genetic inheritance.

What is the consensus estimate for the heritability of IQ?

Experts estimate IQ heritability to be around 50 percent.

What is the Flynn Effect?

The gradual increase in average IQ scores from one generation to the next.

Why is the Flynn Effect significant for the nature-nurture debate?

It contradicts heredity-only claims by showing that IQ scores increase over time without genetic change, proving environmental factors significantly influence intelligence.

What does Kamin's corn-seed analogy demonstrate?

It shows that even if within-group differences are highly heritable, between-group differences in average IQ could still be caused entirely by environmental factors.

What is the difference between within-group and between-group differences?

Within-group differences refer to variations among individuals in the same group, while between-group differences refer to average differences between two or more groups.