In the Biological approach, what does the term heritability estimate refer to?

• A. The proportion of variation in a trait in a population that can be attributed to genetic differences
• B. The degree to which a trait is due to environmental factors
• C. The specific genes responsible for a trait
• D. The average trait value across a population

Answer: (A)

Heritability estimates describe the proportion of variation in a trait across a group of individuals that can be attributed to genetic differences. It’s about how much genetics explains why people differ from one another in that trait, not about an individual’s traits, not about specific genes, and not about the average level of the trait. It’s also population- and environment-dependent: if environments are very similar, heritability can seem higher; if environments vary a lot, it can seem lower. So the statement that best captures this idea is that heritability reflects genetic contributions to variation within a population.