Understanding Intelligence: Theory and Testing

• Intelligence is a general mental ability involving reasoning, planning, problem-solving, and quick learning.

Characteristics of Intelligence

• General mental ability influences performance on all mental tasks, supported by the positive manifold, which are positive correlations among mental tasks in large samples.
• Positive correlations are when someone excels in one mental task, they tend to perform well on others.
• Mental speed is the ability to process information quickly.

Intelligence Tests (IQ Tests)

• They measure intelligence relative to others in the same age group.
• Wechsler and Stanford-Binet tests are age-normed.
• They measure verbal, math, spatial, and memory abilities.
• Predictive validity is that IQ tests can predict work and school outcomes.

Binet and Simon's IQ Test

• Two French researchers created a test to identify children at risk of failing in school at the request of the Paris school board.
• Items on the test had to meet two criteria: age sensitivity and school performance prediction.
• Age sensitivity meant items differentiated children in different age groups, following rules similar to multiple-choice questions on college exams.
• They wanted the items able to predict how well the kids would perform academically in school.
• Item types included verbal reasoning, quantitative math problems, spatial ability (building models), and memory (digit span test).
• Later versions were translated into English and became the Stanford-Binet IQ test. It is still used today
• Added IQ scores to measure intelligence compared to other people in their age group

Characteristics of IQ Scored

• They measure intelligence compared to others in the same age group.
• Early Formula for finding the IQ: IQ= Mental Age/Chronological Age * 100
• Mental Age is child's level of cognitive development. Chronological Age is how old the child is at the time of testing.
• Average IQ is 100, meaning the Mental Age and Chronological Age are the same, so MA=CA.
• Below average IQ is less than 100, meaning the Mental Age is less than Chronological Age, so MA<CA.
• Above average IQ is over 100, meaning the Mental Age is more than the Chronological Age, so MA>CA.
• Modern IQ tests (Wechsler tests) use deviation scores (measure deviation from average IQ in SD units).
• Average IQ is 100.
• 1 SD equals 15 IQ points.
• 1 SD above average = 115 (84th percentile). 1 SD below average = 85 (16th percentile).

Bias (group)

• It occurs when test results mean different things for different groups, typically racial groups.
• Item bias definition, procedure, and findings.

Predictive bias

• It occurs when IQ tests predict better outcomes for one group than another.
• Procedure:
  • Minority and majority members take an IQ test.
  • Minority and majority members with the same IQ score are compared on a later outcome, like GPA.
  • Determinization about predicated bias:
  • If minority/majority members with the same IQ score achieve the same outcome later on, then there is no predicted bias.
  • If minority/majority members with the same IQ score achieve different outcomes later on, then there is predicted bias.
• Major IQ tests show no predicated bias.