Problem 2: Intelligence Flashcards
mental abilities
differences among people in their maximum performance in producing correct answers to various problems or questions
–> the capacities to solve problems that demand thinking-related skills
Factor-analytic approach
= analyzes the number of hypothetical components of a construct
Procedure:
A large number of individuals perform different ability tests, then intercorrelations among these tests are determined and factor analysis is conducted
–> on the basis of correlations, the number of factors are determined that describe best people’s performance
Charles Spearman - G factor
–> correlations among various tasks indicated that performance on each task was influenced by a general mental ability - general intelligence
General Intelligence (g) Theory
Variation in intelligence test scores can be explained by two factors
1. A general factor (g factor) that determines performance on ALL tests
2. A set of specific factors that determine performance on single, specific tests
G-loadings = the higher the g-loading of a task, the better indicator of general intelligence
Louis Thurstone - Primary Factors
Instead of g being the most prominent factor of intelligence, there are 7 primary mental abilities –> primary factors
Verbal comprehension, verbal fluency, inductive reasoning, spatial visualization, number, memory, and perceptual speed
The g factor does not properly explain relations among various kinds of mental abilities
J. Paul Guilford - Structure-of-Intellect model
A multifactor theory that claims the existence of 150 independent ability factors that can be organized into three dimensions:
Operations - describes type of mental processing a person carries out
Contents - related to materials being processed
Products - describes how information is stored or processed
Raymond Cattell - Crystallized and Fluid intelligence
Crystallized intelligence - factual knowledge that has been acquired from school and through life and can therefore increase over time
Fluid intelligence - includes the ability to see relationships between ideas and objects and generally decreases as the person gets older
Developmental changes in mean levels of mental ability
On average, people’s levels of g increase rapidly through childhood and continue to increase into late adolescence, and then decrease during old age
–> decline of mental abilities in old age
Biological Bases of Mental Ability - Brain Size
Brain size is positively correlated with mental ability
–> size of the brain and especially certain regions of the brain
Biological Bases of Mental Ability - Nerve conduction velocity
= the speed with which electrical impulses are transmitted between the cells of the brain and the nervous system
–> there is some link between nerve conduction velocity and IQ
–> a shorter duration indicates a higher nerve conduction velocity (a faster brain) - higher IQ
Biological Bases of Mental Ability - Reaction Time
–> the time interval between seeing the stimulus and reacting to it is the reaction time of the participant
–> slower reaction times are associated with lower scores on tests of mental ability
Biological Bases of Mental Ability - Inspection Time
= the length of time that a stimulus must be present before the brain can notice that stimulus
–> people who have longer inspection times tend to have lower scores on mental ability tests
Genetic Influences on Mental Ability
–> differences among children in their levels of mental ability are attributable almost as much to their common environment - to features of their family or household circumstances - as they are to their genetic inheritances
–> as children grow up, the differences in mental ability are more strongly related to their genetic inheritances
–> overall heritability is estimated about 0.50 with additive genetic influences contributing about 0.35 and nonadditive genetic influences the remaining 0.15
Additive genetic influences
the combined effects of genes are simply the sums of the separate effects of each gene
Nonadditive genetic influences
the combined effects of genes are different from what would be expected based on the separate effects on each gene