Psychology: Intelligence
What is the Alfred Binet's equation to quantify IQ?
(Mental age/chronological age) x 100 = IQ
What is Reliability?
- Consistency of a measure - Needs to have a high positive correlation between test 1 and test 2 (r = +0.90)
What is the Wechsler Adult Intelligence Scale (WAIS)?
- Intelligence test administered to individuals aged sixteen and older (16 +) - Test yields a verbal IQ score, a performance IQ score, and a full-scale IQ score (overall summary/composite score) - Standardized to fit a normal curve (every participant gets the same treatment)
What is Standardization?
- Involves uniform testing procedures - Treat every individual person who is taking the test in exactly the same way
What are problems with using mental age to measure intelligence?
- It starts to break down as a construct to make meaningful decisions about intelligence around age 16 - We know that IQ is relatively stable over time, so mental age is not a valid way of testing intelligence
What are the parameters for a normal curve of IQ?
- Mean = 100 - SD = 15
What is the Flynn Effect and how does it support Environmental Contributions to Intelligence?
- Population wise, there is a gradually increase in IQ scores of 3 points every 10 years - Shows that as more kids going to school, technology increases, healthcare becomes better, less children to take care of, decrease in child labor, etc. has an impact on IQ
What are Important Considerations in Psychological Assessment?
- Reliability - Validity - Standardization
What is Validity?
- Truthfulness of the measurement (of intelligence) - Needs to actually measure intelligence
What evidence for Environmental Contributions to Intelligence is there?
1. Child and adoptive mother (r = +.16) If all genetic, r would = 0 2. Impoverished environment leads to a negative correlation between IQ and age. Longer you live in Impoverished environment (healthcare, nutrition, technology), your IQ decreases 3. Enriched environment can increase IQ
What evidence from twins studies shows a genetic contribution to intelligence?
1. Identical twins reared apart (share 100% of genes): r = +0.75 2. MZ together vs. DZ together a. Identical twins reared together (share 100% of genes): r = +0.86 b. Fraternal twins reared together (share 50% of genes): r = +0.60 i. THIS IS DUE TO DECREASED GENETIC SIMILARITY 3. Similarity in IQ scores goes down as genetic similarity goes down
What does the reaction range tell us about the impact of genes + environment?
1. If inherited reaction range is relatively the same between two people, but their IQ scores are relatively different, then the differences are due to environmental factors 2. If environment is relatively the same between two people, but their IQ scores are relatively different, then the differences are due to genetic factors (inherited reaction range)
If Marcie's mental age is 10 and her chronological age is 8, then her IQ is:
125 = (10/8) x 100
Who sought to develop a test to distinguish between developmentally disabled children and "normal" children?
Alfred Binet
It can be inferred from twin studies that differences between: A. DZ twins are most likely the product of environmental factors. B. MZ twins are most likely the product of environmental factors. C. MZ twins and DZ twins are most likely the product of environmental factors. D. MZ twins are most likely the product of genetic factors.
B. MZ twins are most likely the product of environmental factors.
What is the most important way of standardizing an intelligence test?
By using same-aged peers
What major advancement did Alfred Binet contribute to measuring intelligence?
Developed first workable intelligence test in 1905 with multiple subtests (not just math or vocal)
Correlations between the IQ scores of identical twins reared together are higher than the correlations between IQ scores of identical twins reared apart. This finding suggests that __________ influences IQ scores.
Environment
What method did Alfred Binet's intelligence test use to measure IQ? What is it?
Mental age; point in increasing difficulty of items that you can get to
What is phenotype?
Physical features ("Observable" characteristics)
A teacher grades by giving men C's and women A's. This method is:
Reliable
What is genotype?
The makeup of your genes
What is psychological assessment?
The use of specified procedures to evaluate the abilities, behaviors, and personal qualities of people
How do we test intelligence?
Through one's abilities
What are Monozygotic (MZ) and Dizygotic twins (DZ)?
• Monozygotic: Identical twins, 100% • Dizygotic: fraternal, 50%
