What is intelligence?

o     You are set up on a blind date with someone you are told has in I.Q. of 140 (in the top 2.5% of the population). 

o     What do you think about this person?

Origins of the I.Q. Test

o     French government at around 1900 became concerned with developing public education

o     Not wanting to waste their money on non deserving children they asked Alfred Binet to design a test that would pick the children who where intellectually the best

1904: Binet designed the Intelligence or I.Q. test

§       Intelligence Test

§       a method of assessing an individual’s mental aptitudes and comparing them to those of others, using numerical scores

How did Binet go about designing an intelligence test?

o     He came up with questions he thought could be answered by children at different ages

n      Two year olds:  can they stack blocks, can they point to a dog, etc.?

n      Six year olds: can they solve a simple puzzle, do they know what “gigantic” means?

n      Fourteen year olds: do they know what “prodigious” means, do they know what insulations does on a wire?

How did Binet go about designing an intelligence test?

o     Binet empirically tested questions until he found items that could typically be answered by children of different ages

n      E.g.: Four year old questions

n               Five year old questions

n               Six year old questions, etc.

Scoring the Binet Intelligence Test: Assume a 6 year old is given the test

o      He answers all the questions meant for six year olds– how much “mental age” do we give him?

n      6 years

o      He also answers 50% of the questions meant for seven year olds– how much “mental age do we give him?

n      Another 6 months

o      He answers 25% of the eight year old questions

n      Add another 3 months

o      He can’t answer any of the nine year old questions

What’s his Mental Age?

o     6 years  (six year old questions)

o     Plus 6 months (seven year old questions)

o     Plus 3 months (eight year old questions)

o     Total = 6 year and 9 months or

n      6.75 years

o     Thus, his mental age is greater than his physical or chronological age

Binet’s Formula: Intelligence Quotient



o     If someone’s mental age is identical to their chronological, what is their I.Q. ?

o     100

o     If someone’s mental age is less then their chronological age, what is their I.Q. ?

o     Less than 100

o     What is the mean or average I.Q.

o     By definition =  100

Important Insight

o     Binet’s questions were not developed based on any “theory” of children’s knowledge

o     Binet made no assumptions about what why a child was slow, average, or precocious

o     He was only concerned with developing an empirical test that could be used to separate or measure the children

Current Intelligence Tests

o      Since Binet, the test was translated into English and adapted for the U.S. by Lewis Terman of Stanford University

n      Terman didn’t think many of the questions fit American norms

o      Terman extended the test to adults and “superior adults”– he came up with questions on few adults could answer

o      Now known as the Stanford-Binet Intelligence Test or Quotient

Wechsler Tests

o     David Wechsler developed a similar set of tests known as the

n      Wechsler Adult Intelligence Scale  (WAIS)

n      Wechsler Intelligence Scale for Children (WISC)

o     Wechsler Tests are now the most popular that are administered individually

o     In addition to the total score, it has both a “verbal” and “performance” (non-verbal) score

Standard Deviation of I.Q. test is 15

Intelligence (aptitude) vs. Achievement

o     Intelligence or aptitude tests are meant to predict your general ability to learn new skills

o     Achievement tests are meant to reflect what you have learned—for example, from school

o     What are SAT’s ?

What are each of these– intelligence or achievement?

Are intelligence tests accurate or useful?

o     ALL tests are assessed by whether they are

o     Reliable

o       and

o     Valid

Assessing Intelligence

§        Reliability

§       the extent to which a test yields consistent results

§       assessed by consistency of scores on:

§         two halves of the test

§         alternate forms of the test

§         retesting

§        Validity

§       the extent to which a test measures or predicts what it is supposed to

Assessing Intelligence

§        Predictive Validity

§       success with which a test predicts the behavior it is designed to predict

§       assessed by computing the correlation between test scores and the criterion behavior

§       also called criterion-related validity

What do intelligence tests predict?

o     Success in life, e.g., jobs, money or power?

o     Happiness, e.g., success in relationships?

o     School success?

o     Correlation between I.Q. and grades is about +. 60


Why the limited validity?

o     Perhaps there is not a single, overall type of intelligence. 

o     Rather, maybe intelligence consists of different types of abilities

The Nature of Intelligence
Gardner's Frames of Mind

o     Multiple Intelligences

n      Gardner’s theory that there are seven types of intelligence:

o       Linguistic intelligence

o       Logical - mathematical intelligence

o       Spatial intelligence

o       Musical intelligence

o       Bodily-kinesthetic intelligence

o       Interpersonal intelligence

o       Intrapersonal intelligence

The Nature of Intelligence
Sternberg's Triarchic Theory

o     Triarchic Theory of Intelligence

n      Sternberg’s theory that there are three kinds of intelligence: analytic, creative, and practical.

o      Analytic - “Components”

n      Comparing, analyzing, and evaluating

n      This type of process correlates best with IQ

o      Creative - “Experiential”

n      Inventing or designing solutions to new problems

o      Practical - “Contextual”

n      Adapting to the contexts of everyday life

The Nature of Intelligence
Sternberg's Triarchic Theory