EFO: Intelligence / Individual Differences

Q: What is the definition of intelligence? What is the theory of general “g” intelligence?

A:

• Intelligence: The ability to learn from experience, solve problems, and adapt to new situations.

• General “g” intelligence (Spearman): A single underlying factor that accounts for overall differences in cognitive ability across tasks.

Q: What is the Flynn effect? What are its implications and possible causes?

A:

• Flynn effect: The observed rise in average IQ scores over generations.

• Implications: Intelligence test norms need periodic updating; IQ is influenced by environment.

• Possible causes: Improved nutrition, education, health, complexity of daily life, and environmental stimulation.

Q: How stable is IQ over time?

A: IQ is moderately stable, especially after childhood; correlations are stronger in adolescence and adulthood than early childhood.

Q: What are Monozygotic (MZ) twins and how are they different from Dizygotic (DZ) twins?

A:

• Monozygotic (MZ) twins: Identical twins from a single fertilized egg, share 100% of genes

• Dizygotic (DZ) twins: Fraternal twins from two separate eggs, share ~50% of genes, like regular siblings

Q: Why are MZ and DZ twins often used in behavioral genetics research?

A: Because they allow researchers to compare the influence of genetics vs. environment on traits, given their different levels of genetic similarity.

Q: Are siblings/fraternal twins genetically identical or just similar?

A: Siblings and DZ twins are genetically similar (~50%), not identical.

Q: How can twin studies be used to study the effects of nature vs. nurture?

A: By comparing trait correlations in MZ twins vs. DZ twins, researchers can estimate heritability (genetic influence) and environmental influence on traits.