Introduction• Intelligence (IQ): one’s overall cognitive
ability, including knowledge, memory, mental quickness, and problem solving
• Standardized IQ Tests:– Vocabulary, arithmetic, pattern completion,
puzzles, information, memorizing numbers
• Most cognitive tasks provide a rough measure of intelligence: ACT, SAT, GRE, exams, papers, social problem solving
“Intelligence” Doesn’t Exist?
“There’s no such thing as intelligence. It’s just used to label people as smart or dumb, and these labels are meaningless. The ACTs are worthless, and colleges should stop using them.”
Sorry, Mr. Hippie• “Intelligence” is a valid construct (concept)
• Validity: any construct, such as intelligence, is valid if it predicts relevant outcomes
• Intelligence tests predict…– Occupational status − Pronunciation– Success at work − Mental math– College grades − Criminality– Emotional Adaptation − Learning speed
• In a few hours, most psychology students could design a simple intelligence test that would predict college grades (r = .50)
• Intelligence tests correlate r = .30 to .90 with scores on any cognitive task (r = .75 on average)
• Larger correlations than any other area of psychology
Multiple Intelligences?
“Everyone has different abilities. Someone can be bad at one type of task and good at something else. There are many types of intelligence, and most people are good at something.”
Sorry, Dr. Sternberg• Sternberg (3), Gardner (8), Guilford (150)
– Not supported by research
• General mental ability (g): All of the different types of intelligence are so highly correlated, they are considered to measure the same thing
• Smart people do well on most tasks
• In rare instances, it may be useful to examine fluid vs. crystallized intelligence
IQ is Entirely Heritable?
“Intelligence is solely the product of good genes, and those that fail to succeed in society are genetically inferior”
Sorry, Mr. Murray• Like most traits, intelligence is strongly
influenced by both genes and environment
• Children: family environment matters most
• Adults: genes play a bigger role, as people choose environments that maximize their genetic potential
• Teratogens, malnutrition, poorly funded schools, and racism may have huge effects
Racist IQ Tests?
“Psychologists are racists. IQ tests are just used to discriminate against minorities, who score lower on these tests. Psychologists should be ashamed.”
Sorry, Ms. Grace• African Americans score 10 point less
• Unscrupulous/ignorant psychologists have occasionally used this to say that minorities are inherently inferior
• BUT we know IQ is not entirely genetic
• Lower IQ scores are likely a result of discrimination in education (bad schools)
• IQ tests just show that we need to level the educational playing field
It’s Unchangeable?
“Intelligence is genetic and therefore unchangeable. The smart will always be on top, and the slow will always be in their way.”
Sorry, Mr. Herrnstein
• Intelligence is a relatively stable trait, but change is possible
• “Verbal” or “crystallized” intelligence is based on knowledge of information
• Flynn effect: IQ increases each generation
• IQ shifts when people enter adulthood
• IQ changes reliably with age
Crystallized
Fluid
IQ is Not Important?
“Who cares about IQ? Success depends more on personality, motivation, hard work, paying attention, and who you know”
Sorry, Ms. Coulter• IQ is the best predictor
• Motivation and personality are important too
• But it’s hard to measure motivation, and personality measures are easy to fake
• Generally, IQ tests are incredibly useful– Choosing employees or students– Helping people who are having academic problems:
too smart, too slow, learning disorder
Michael Hoerger
To cite this lecture:
• Hoerger, M. (2007, April 9). Intelligence (IQ) and Development. Presented at a PSY 220 lecture at Central Michigan University.
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