Intelligence does moderately correlate with brain size Remember: experience alters the brain Rats in stimulating environments develop thicker cortexes

Highly educated people die with more synapses Higher intelligence scores were linked with more grey matter (neural bodies) in specific areas known to be involved in memory, attention, and language.

Neuroscientists study the brain’s functioning to find explanations for intelligence Frontal Lobe lights up when contemplating verbal and spatial questions Suggests this may be a “workspace for organizing and coordinating information” Perceptual speed: those who perceive quickly tend to score somewhat higher on intelligence tests

Neurological speed: highly intelligent people’s brain waves register a simple stimulus more quickly and with greater complexity We don’t know WHY fast reactions on simple tasks predict intelligence test performance Neurological approach to understanding intelligence is new – right now we have more questions than answers

Intelligence test: method for assessing an individual’s mental aptitudes and comparing them with those of others, using numerical scores Intelligence is whatever intelligence tests measure Origins Western cultures emphasize the individual, so the question follows how & why individuals differ

Assumed all children follow the same course of development, but some develop more rapidly Mental age: measure of intelligence test performance, the chronological age that most typically corresponds to a given level of performance

Wanted to use Binet’s test but found that it did not work for American kids Stanford-Binet: widely used American revision of Binet’s original intelligence test William Stern (Germany) used these tests to create the intelligence quotient (IQ): defined originally as the ratio of mental age to chronological age multiplied by 100 This formula works well for children, but not for adults; today IQ measures your performance relative to others of the same age

World’s first mass administration of an IQ test US government developed the test to evaluate new immigrants and 1.7 million army recruits Boosted the credibility of psychology Stimulated public debate about the validity of the test & its implications for American democracy

Aptitude tests: designed to predict a person’s future performance; aptitude is the capacity to learn Achievement tests: designed to assess what a person has learned Wechsler Adult Intelligence Scale (WAIS): most widely used intelligence test; contains verbal and performance subtests

1.Standardization: defining meaningful scores by comparison with the performance of a pre- tested standardization group Normal curve: symmetrical bell-shaped curve that describes the distribution of scores; most scores fall near the average and fewer and fewer scores lie near the extremes 2.Reliability: extent to which a test yields consistent results, as assessed by the consistency of scores on 2 halves of the test, on alternate forms of the test, or on retesting.

3.Validity: extent to which a test measures or predicts what it is supposed to 1.Content validity: extent to which a test samples the behavior that is of interest 2.Predictive validity: success with which a test predicts the behavior it is designed to predict Criterion: the behavior that a test is designed to predict (such as college grades on the SAT)