What is intelligence
a very general mental capacity that, among other things, involves the ability to reason, plan, solve problems, think abstractly, comprehend complex ideas, learn quickly from experience
What is the benefit of using IQ test as a definition of intelligence?
It’s an operational definition so it can be measured
On an IQ test, what is the mean and standard deviation?
- Mean = 100
- Standard deviation = 15
Does Francis Galton believe that nature or nurture plays more of a role in determining intelligence?
Believed there was no escaping from the conclusion that nature prevails enormously over nature
What is eugenics?
The study of or belief in the possibility of of improving the qualities of the human species or a human population, especially by such means as discouraging reproduction by people presumed to have inheritable undesirable traits (negative eugenics) or encouraging reproduction by people presumed to have inheritable desirable traits (positive eugenics)
What does Radical Behaviorism suggest about intelligence?
- Our upbringing and environment determines our future more than eugenics
- Suggest our intelligence is more related to our environment than our genetics
What is differential psychology?
- Differential psychology is the branch of psychology concerned with individual and group differences in psychological traits and behavior
- Differential psychologists study twins and adoptees to show that both nature and nurture contribute to these differences
How does comparing MZ to DZ twins help with controlling the environment?
- A twin study is an example of a natural experiment
- Environmental overlap is 100% for both
- If genetics is the major source of individual differences, MZ twins will be more similar than DZ twins
- If rearing environment is the major source of individual differences, MZ twins and DZ twins will be equally similar
Do MZ or DZ twins perform more similarity on IQ tests?
MZ twins perform more similarly on IQ tests
How are adoption studies important in determining the role of nature vs. nurture?
They show two individuals with exactly the same environment, but no similarity in their genetics
What are the key findings from twin studies & adoption studies?
- MZ twins are more similar than DZ twins (genetics are important)
- MZ twins are not perfectly similar (environment is important)
- Twin similarity for psychological traits is not very different from similarity for physical traits
- Adopted siblings are only slightly similar (sharing a rearing environment does not make people very similar)
What is the Minnesota Study of Twins Reared Apart?
A scientific study done on identical twins
What are the findings of the differences between MZ twins reared apart versus together?
- MZ twins are very similar even when reared apart (genetics are important)
- MZ twins reared apart are not perfectly similar (environment is important)
- MZ twins reared together are not much more similar then MZ twins reared apart
- Sharing a rearing environment does not contribute much to twins similarity
Who are Charles Spearman, Afred Binet, David Wechsler(what did they each contribute to our understanding of intelligence)?
- Charles Spearman = Looked at measures of intellectual performance
and found they were all correlated with each other (also created General intelligence: g) - Afred Binet = measured mental age and invented willaim stern’s Intelligence Quotient (IQ = mental age/chronological age x 100)
- David Wechsler = Created the wechsler-Bellevue intelligence sale which looked at verbal IQ vs. Performance IQ and created the most frequently given IQ test in the world (WAIS IV)
What is general intelligence - also called “g”?
- a construct that is made up of different cognitive abilities
- These abilities allow people to acquire knowledge and solve problems
- This general mental ability is what underlies specific mental skills related to areas such as spatial, numerical, mechanical, and verbal abilities
What is the most frequently given IQ test worldwide?
WAIS IV (2008) is the most frequently given IQ test in the world
What are the four components of a full scale IQ?
- Verbal Comprehension Index (vocabulary, similarities, information)
- Perceptual Reasoning Index
- Working Memory Index (arithmetic)
- Processing Speed Index (digest-symbol coding, symbol-search)
Verbal vs. Perceptual Reasoning
- verbal = A measure of an individual’s ability to understand, learn and retain verbal information and to use language to solve novel problems
- Perceptual = A measure of an individual’s ability to understand visual information and to solve novel abstract visual problems
What percentage of individuals in a population are considered gifted and intellectually disabled?
2.3% for both
Is the WAIS-IV reliable and valid?
The WAIS IV has a split half reliability of .97
And a 1 year test-retest reliability of .90
By age 10, IQ correlates about .70 with IQ at age 40
Are IQ scores stable over time?
- IQ scores generally increase over time
- the older you are, the more stable your IQ score will be
How does IQ score change over the course of your life?
- Performance is preserved for world knowledge over time
- Everything else decreases
- IQ is valid (social outcomes, academic outcomes, etc)
What is a higher IQ positively related to? (note: you don’t need to memorize the list, try to understand the big picture ideas)
- socioeconomic status
- education
- age
What things in the environment can affect your IQ?
- Neurotoxins = Antenatal, Postnatal
- Nutrition = General Nutrition, Breast Feeding
- Education = Early Education Enrichment Programs, Schooling
- Rearing Environment (enrichment)
- Birth order and family size
- Cultural specificity
