Intelligence
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Defining Intelligent Behavior
• What is intelligence?
• Intelligence– the capacity to understand the world, think
rationally, and use resources effectively when faced with challenges
• Intelligence Tests– tests devised to identify a person’s level of
intelligence
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Measuring Intelligence
• Mental age– the average age of children taking the Binet test who
achieved the same score
• Chronological age– physical age
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Measuring Intelligence
IQ=MA x 100 CA
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Tests of IQ
• Stanford-Binet Test
• Wechsler Adult Intelligence Scale-III (WAIS-III)
• Wechsler Intelligence Scale for Children-III (WISC-III)
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Achievement and Aptitude Tests
• Achievement Test– a test meant to ascertain a person’s level of
knowledge in a given subject area
• Aptitude Test– a test designed to predict a person’s ability in a
particular area or line of work– SAT, ACT
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Reliability and Validity
• Reliability– the concept that tests measure consistently what
they are trying to measure
• Validity– the concept that tests actually measure what
they are supposed to measure
• Norms– standards of test performance
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Alternative Formulations of Intelligence
• G or G-factor– an early theory that assumed there was a general factor
for mental ability
• Fluid Intelligence• reflects reasoning, memory, and information
processing capabilities
• Crystallized Intelligence• information, skills, and strategies that people have
learned through experience
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Alternative Formulations of Intelligence
• Gardner’s Seven Intelligences:• Musical intelligence
• Bodily kinesthetic intelligence
• Logical-math intelligence
• Linguistic intelligence
• Spatial intelligence
• Interpersonal intelligence
• Intrapersonal intelligence
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Contemporary Approaches
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Variations in Intellectual Ability
• Mental Retardation– a significantly subaverage intellectual
functioning that occurs with related limitations in two or more of the adaptive skill areas
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Variations in Intellectual Ability
• mild retardation– IQ = 55-69
• moderate retardation– IQ = 40-54
• profound retardation– IQ below 25
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Variations in Intellectual Ability
• Causes of mental retardation– identifiable biological reason (e.g. Down’s
Syndrome)– familial retardation
• Care and Treatment– least restrictive environment– mainstreaming– full inclusion
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Variations in Intellectual Ability
• The Intellectually Gifted– two to four percent of the population who have
IQ scores greater than 130– social stereotypes of gifted people
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Individual Differences in Intelligence
• Are traditional IQ tests culturally biased?
• Are there racial differences in intelligence?
• To what degree is intelligence influenced by the environment and to what degree by heredity?
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The Relative Influence of Heredity and of Environment
• Culture-fair IQ test– a test that does not discriminate against
members of any minority group
• Heritability– a measure of the degree to which a
characteristic is related to genetic, inherited factors
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The Flynn Effect