Intelligence - Umay Suanda PDF

Preview

Summary

Umay Suanda...

Description

Intelligence Lectures (04/15) & (04/20) Behavioral Genetics ● What does this term refer to? (21 A) ○ Behavioral Genetics: a field of scientific research that uses genetic methods to investigate individual differences in behavior. It exploits patterns in how related people are genetically, and connects those patterns to how similar they are in behavior. ● Be prepared to reason about how twin studies inform us about the role of nature and nurture in our psychological capabilities. (21 A) ○ Plato = nature = genes while Aristotle = nurture = environment ○ Twin resemblance is solely due to genetic variation. But, just because a trait (e.g. intelligence) is “heritable,” it does not mean environment doesn’t matter. Example is height ● Understand how identical and fraternal twins are different? Be prepared to use the terms “identical” / “fraternal” and “monozygotic” / “dizygotic” interchangeably ○ Monozygotic (identical) twins: shared environment- shared genes 100% ○ Dizygotic (Fraternal) twins: shared environment- shared genes 50% Two-Factor Theory of Intelligence ● What is it? What did we learn from the Two-Factor Theory of Intelligence? (21 B) ○ Charles Spearman divided intelligence into two parts: general intelligence (g) and specific intelligence (s). ○ The two factor theory states that 1. Different IQ subtests were positively correlated. Correlation argues to be driven by “general intelligence” (or “g”). 2. “g” is supplemented by “s,” intelligence specific to the subtests.

Fluid vs. Crystalized Intelligence ● What do they refer to? Be prepared to reason about the two types of intelligence/identify in examples. (21 B) ○ Subsequent analysis suggested something more complex than two factors. They are both m = “middle-level intelligence” ○ Crystalized Intelligence ( gc ): ability to apply knowledge that was acquired through experience (vocabulary, facts) ■ Example test question could be: To be choleric is to be- (a) overweight (b)

bad-tempered (c) pleasant (d) sad ○ Fluid Intelligence ( gf ): ability to solve and reason novel problems. ■ Example question could be you’re given a picture of shapes and patterns but a ? is in place of one of them so they ask you what that shape/pattern will be. (Raven’s Progressive Matrices) ● What is the psychological and neuroscientific evidence that these two forms of intelligence are distinct from one another? (21 B) ○ 1. They exhibit different development trajectories. Fluid intelligence decreases with age while crystalized intelligence increases with age. ○ 2. They have different neural correlates ■ Fluid intelligence: Dorsal prefrontal cortex. Damage to DL-PFC selectively impairs gf with no/little effect on gc . More recent theories stress the connection between frontal and parietal areas (Parietofrontal integration theory). ■ Crystalized Intelligence: Less obvious neural correlate (likely more distributed across the neocortex?) Intelligence Quotient (IQ) ● What is the difference between Ratio IQ and Deviation IQ score? ○ Ratio IQ: mental age divided by chronological age ○ Deviation IQ: measures how a person compares to other people the same age ● How are IQ scores distributed in the population? ○ Bell curve distribution Behavioral Genetics of IQ ● What have we learned from twin and adoption studies about the role of genes and environments on IQ? (21 C) ○ Twin-Design Study: Shared Environment

Shared Genes

Monozygotic (Identical)

YES

100%

Dizygotic (Fraternal)

YES

50%

○ If Monozygotic twins are more similar than dizygotic twins in a behavior/trait, then that behavior/trait must have a large genetic component. ○ If Monozygotic twins are equally similar to dizygotic twins in behavior/trait, then that behavior/trait must have a large environmental component

○ ● What have we learned from research on identical twins reared apart? (21 C) ○ Shared Environment

Shared Genes

Monozygotic (Identical)

YES

100%

Monozygotic (reared apart)

NO

100%

Dizygotic (Fraternal)

YES

50%

○ ○ Twin resemblance is solely due to genetic variation. ● What is meant by Shared and Nonshared Environments? (22 A) ○ Environment has an effect, but it is the non shared environment that has a stronger effect. ○ Shared Environment: Factors experienced by all members of a household (e.g.. Shared parenting styles, shared peer groups, shared school/community). Matters less than you think. ○ Non-shared Environment:Factors not experienced by all members of a household (e.g. different experiences with parents, peers, teachers, etc.). Matters more than you think. Be familiar with the following finding related to IQ and what they say about the contribution of nature and nurture on IQ: (22 A) ● The Flynn Effect (22 A) ○ On average, IQ scores have increased over the past 120 years. This could be based on the environment (nurture). Differences in nutrition, health, schooling? Increase reliance on “analytical thinking”

● Birth Order Studies (22 A) ○ Older siblings reliably score higher on IQ tests. This could be based on environment (nurture). Differences in parenting, stimulation, resources? The role of teaching the younger siblings? ● High-SES Adoption studies (22 A) ○ Study of children adopted into High SES families where they compared to their adopted siblings and compared to biological siblings who were not adopted. ○ Adoption and SES has positive effects on IQ, school performance ● The role of genes and environment on IQ as a function of age (22 B) ○ A pair of 80-year-old identical twins are more similar than a pair of 80-year-old fraternal twins. A pair of 4-year-old twins are not that much similar to each other than a pair of 4-year-old fraternal twins. ● The Genetic Amplification Effect (22 B) ○ Small genetic effects early in development are magnified over time. ○ “As children grow up, they increasingly select, modify, and create their own experiences in part based on their genetic propensities” ● The role of genes and environment on IQ as a function of SES (22 B) ○ Genetic influences on IQ are stronger for those in higher-SES environments than for those in lower-SES environments ○ Why? There is a minimum environment for full genetic potential to be developed. Facilitative environments provide people (and their genes) more opportunities to select their environment. ● The role of genes and environment on IQ as a function of IQ level (22 B) ○ The role of the environment lasts longer in the lives of high-IQ children ○ Having a higher-IQ prolongs sensitivity to the environment, openness to experience....