Intelligence
• intelligence: usually defined as the ability
to profit from experience, acquired
knowledge, think abstractly, act
purposefully, and/or adapt to changes in
the environment.
Theories of Intelligence
• Spearman’s g-factor: a general intellectual
ability assumed by many theorists to underlie
specific mental abilities and talents
• Cattell’s clusters
– crystallized intelligence: abilities like reasoning and
verbal and numerical skills
• highly influenced by experience and formal education
– fluid intelligence: visual and spatial imagery, rote
memory.
• less influenced by experience and education
Theories of Intelligence
• Howard Gardener
– theory of multiple intelligence proposes that
intelligence comprises many separate abilities
each of which is relatively independent of
each other.
– Types of intelligence: Logical-mathematical,
linguistic, spatial, musical, bodily-kinesthetic,
interpersonal, and intrapersonal
Intelligence Tests
• Alfred Binet
– Memory, vocabulary, and perceptual
discrimination
• IQ “intelligence quotient”: a measure of
intelligence originally computed by dividing
a person’s mental age by his or her
chronological age and multiplying by 100
Intelligence Tests
• Wechsler Adult Intelligence Scale and
Wechsler Intelligence Scale for Children
– divided into two parts: verbal and
performance
– Vocabulary, spatial, speed, similarities,
information
• 68% of population has IQ scores between
85 and 115.
• 95% of population has IQ scores between
70 and 130.
Criticisms of IQ tests
• Content- tests assess ability in only a very
narrow range of skills
– passive verbal understanding, ability to follow
instructions; common sense; scholastic aptitude
• Tests test ability to take tests
– close correlation between IQ scores and school
performance
– stereotype threat: a burden of doubt a person feels
about his or her performance, due to negative
stereotypes about his or her group’s abilities.
Criticisms of IQ tests
• bias against minorities
– require mastery of English
– questions are culturally based
– Speed
• used inappropriately
– don’t measure motivation, emotion, and
attitude which affects performance in life
– Study by Terman which followed 1500 of top
1% of IQ scores
• most differences attributable to motivation
Contributing factors: heredity
• Heredity- intelligence is partly inherited
• correlation between monozygotic twins reared
together very high
• correlation between monozygotic twins reared
apart also high
– higher than siblings reared together
• However, monozygotic twins share similar
environment because adoption agencies tend to
match environments and they also shared same
prenatal environment
Contributing factors: environment
• Environment also affects intelligence
• prenatal environment impacts IQ
– Prenatal vitamins
• IQ of children in orphanages in Iowa (Skeel,
1930)
– Orphans who had little adult interaction had
“subnormal” IQ
– Children who had were placed in adult ward had
increased IQ from the retarded range to normal.
– Concluded that children need to have someone to talk
to them, play with them, and teach them to be able to
reach their full potential.
Contributing factors: motivation
• Motivation affects intellectual ability
• Comparing Chinese and Japanese
students with American students
– Beliefs: American students and parents more
likely to believe that ability is innate
– Standards: American parents have lower
standards for their children’s performance
– Values: American students don’t value
education as much as Asian students.
Contributing factors: intervention programs
• Intervention Programs- Milwaukee Project intervened
in children’s family life to offset the negative effects of
cultural and socioeconomic deprivation
– 40 poor pregnant women whose average IQ was 75
– 20 were given job training and had their children in
the infant education center until they were 6 years
old.
– 20 were not given any special treatment, just periodic
IQ testing
– Children who were in the infant education center had
average IQ of 126, 30 points higher than children who
did not participate (m=94)
Contributing factors: intervention programs
• Head Start started in 1965
– Provides low-income preschoolers age 3-5
educational and social skills before they get to
school
– Parents are also encouraged to participate in
activities and administration of program
– Graduates of Head Start have boost in
cognitive abilities, stay in school longer, more
likely to graduate from college