How do we Assess Intelligence? Alfred Binet and Theodore Simon set out to figure out a concept called a mental age (what a person of a particular age should know). They discovered that by discovering someone’s mental age they can predict future performance. Hoped they could use test to help children, not label “intelligence”

Terman and his IQ Test Used Binet’s research to construct the modern day IQ test called the Stanford-Binet Test. IQ=Mental age/Chronological age X 100. A 8 year old has a mental age of 10, what is her IQ? A 12 year old has the mental age of 9, what is his IQ? A boy has the mental age of 10 and an IQ of 200, how old is he?

Problems with the IQ Formula It does not really work well on adults, why? If a 60 year old man does as well as an average 35 year old then his IQ would be 50!!!!!! That makes no sense!!!!!

Wechsler Tests More common way to give IQ tests….does not use the formula but uses the same scoring system. WAIS WISC WPPSI

How do we construct an Intelligence Test? Standardized: the questions have been piloted on similar populations and the scores fall on a normal distribution. Reliable: The extent which a test yields consistent results over time. Test-Retest, Split-halves Methods. Validity: The extent to which a test measures what it is supposed to measure. Content or Predictive.

Normal Distribution In a normal distribution, the mean, median, and mode are all the same!!

Reliability A test is reliable when it yields consistent results. To establish reliability researchers establish different procedures: Split-half Reliability: Dividing the test into two equal halves and assessing how consistent the scores are. Reliability using different tests: Using different forms of the test to measure consistency between them. Test-Retest Reliability: Using the same test on two occasions to measure consistency. OBJECTIVE 11| Explain what it means to say that a test is reliable.

Validity Reliability of a test does not ensure validity. Validity of a test refers to what the test is supposed to measure or predict. Content Validity: Refers to the extent a test measures your definition of the construct Predictive Validity: Refers to the function of a test in predicting a particular behavior or trait. For instance, we might theorize that a measure of math ability should be able to predict how well a person will do in an engineering-based profession. OBJECTIVE 12| Explain what it means to say that a test is valid, and describe two types of validity.

Extremes of Intelligence Akrit Jaswal

Extremes of Intelligence A valid intelligence test divides two groups of people into two extremes: the mentally retarded (IQ 70) and individuals with high intelligence (IQ 135). These two groups are significantly different. OBJECTIVE 14| Discuss the two extremes of the normal distribution of intelligence.

Mental Retardation APA “significantly sub-average general intellectual functioning . . . that is accompanied by significant limitations in adaptive functioning.” Must appear before the individual is 21 years old. Implies an inability to perform at least some of the ordinary tasks

Causes Not much is known for reasons behind mild retardation (90% of all diagnosed) PKU (phenylketonuria) – liver fails to produce an enzyme necessary for early brain development Down Syndrome – is a genetic disorder caused by the presence of all or part of an extra 21st chromosome. Fragile X syndrome – boys harder hit due to only one X chromosone

Giftedness Terman – (1925)“academic talent and measured by an IQ in the top two percent of the population.” Renzulli – (1978) above average general ability, exceptional creativity, and high levels of commitment Motivation added in the 90s

Discussion Questions Should public schools practice inclusion? Should public funds be used for gifted classes? Is singling out certain students as gifted elitist? Are AP classes for gifted students?

Flynn Effect In the past 60 years, intelligence scores have risen steadily by an average of 27 points. This phenomenon is known as the Flynn effect.

Does Intelligence Change Over Time? By age 3, a child’s IQ can predict adolescent IQ scores. Depends on the type of intelligence, crystallized or fluid.

Early Theories of Intelligence R. B. Cattell Identified two clusters of mental abilities Crystallized intelligence includes abilities such as reasoning and verbal skills Fluid intelligence includes skills such as spatial and visual imagery, rote memory, and the ability to notice visual details While education can increase crystallized intelligence, it was not thought to have any effect on fluid intelligence

Stability or Change? Intelligence scores become stable after about seven years of age. In numerous studies, stability of intelligence scores have been determined (Angoff, 1988; Deary et al., 2004). OBJECTIVE 13| Describe the stability of intelligence scores over the life span.