Which statement best defines heritability in psychology?

Which statement best defines heritability in psychology?

• A. Heritability quantifies the genetic contribution to variation within a population and acknowledges environmental influence; it is not a fixed property of individuals.
• B. Heritability is the percentage of a trait determined by genes in an individual.
• C. Heritability means a trait cannot be modified by environment.
• D. Heritability is 100% for all psychological traits.

Answer: (B)

Heritability describes how much of the differences in a trait across individuals in a population are due to genetic differences, while allowing for environmental influences. It’s about variation in a group, not a property of any single person. Because it reflects population-level variation, it isn’t a fixed percentage for an individual or for a given trait in every context. That’s why saying the trait in an individual is determined by genes in a fixed percentage isn’t accurate—and why environment can still shape outcomes even when genetics play a role. It also isn’t 100% for all psychological traits, since both genes and environment contribute and interact to produce observed variation.

Heritability describes how much of the differences in a trait across individuals in a population are due to genetic differences, while allowing for environmental influences. It’s about variation in a group, not a property of any single person. Because it reflects population-level variation, it isn’t a fixed percentage for an individual or for a given trait in every context. That’s why saying the trait in an individual is determined by genes in a fixed percentage isn’t accurate—and why environment can still shape outcomes even when genetics play a role. It also isn’t 100% for all psychological traits, since both genes and environment contribute and interact to produce observed variation.