HDE100A Chapter 3 Review

What is heritability?

A statistic estimating how much variation in a trait within a particular population and environment is associated with genetic differences.

Does high heritability mean a trait cannot change?

No. A trait can be highly heritable and still change when environmental conditions change.

Does heritability tell you how much of one person's trait is genetic?

No. It describes variation across a population, not the cause of an individual's outcome.

Why does heritability depend on context?

Genetic and environmental variation differ across populations, settings, and time periods.

What is differential susceptibility in genetics?

The idea that sensitivity to any particular experience differs from one person to another because of the particular genes each person has inherited, or because of the events that the person experienced years earlier.

What is gene-environment interaction?

When the effect of genes depends on the environment, or the effect of an environment differs according to genetic differences.

What is gene-environment correlation?

When genetic differences are associated with the environments people experience or seek.

What is epigenetic methylation?

A chemical process involving methyl groups that can influence gene activity without changing the DNA sequence.

What is genetic counseling?

Consultation with trained professionals to understand genetic risks, testing, and possible implications.

What is trisomy 21?

A chromosomal condition usually involving an extra copy of chromosome 21, commonly associated with Down syndrome.

Nearsightedness is about 75% heritable, yet US rates rose from 25%

to 42% in about 30 years. What was the key lesson from this example?

A highly heritable trait can change substantially across decades, showing that heritability does not mean a trait is fixed.

What is the main point of Dick (2022) in the lecture notes?

Environments can amplify or dampen genetic predispositions, and understanding sensitivity may help target support.

How can genes shape the environments people experience?

Genes can be associated with environments people seek out and with how other people respond to them.

What did Plomin emphasize about genes?

Genes are important influences on individual differences and should be considered when studying development.

Why should a strong claim that parenting does not matter be treated cautiously?

Genetic influences interact with environments, and parental behavior and circumstances can still affect development.

What is genetic nurture?

Parents' genes may influence a child's outcome through the environment the parents create, even when the child does not inherit those particular genes.

What did the Nuffield Foundation (2021) report discuss?

Parents' non-inherited genetic variants can be associated with children's educational outcomes through parental traits and environments.

What did Armstrong-Carter et al. (2020) study?

Around 2,000 UK mother-child pairs, examining mothers' education-related genetic scores and children's outcomes at ages 4–7.

What did Armstrong-Carter et al. find about prenatal circumstances?

Prenatal health and financial circumstances statistically accounted for part of the association between mothers' education-related genetic scores and children's outcomes.

Does Armstrong-Carter et al. prove that maternal genes directly cause child outcomes?

No. The findings are observational associations and do not by themselves prove causation.

Why might prenatal circumstances represent more than pregnancy alone?

Health and financial conditions may continue after birth, so prenatal measures can also reflect longer-term family circumstances.