Psychology MCAT Practice Exam

What does heritability refer to in the context of behavioral genetics?

1. The proportion of variation in a trait due to environmental factors

2. The extent to which genetics account for variation in a trait

3. The influence of upbringing on behavior

4. The shared traits between siblings

The correct answer is: The extent to which genetics account for variation in a trait

Heritability in the context of behavioral genetics refers to the extent to which genetic differences among individuals in a group contribute to individual differences in a trait, such as intelligence or personality. This concept is quantified as a proportion, indicating how much of the variability in that trait can be attributed to genetic factors as opposed to environmental influences. It's important to distinguish heritability from the influence of upbringing or shared environments; heritability specifically concerns genetic variance. For example, a heritability estimate of 0.60 would imply that 60% of the variability in a trait within a specific population can be explained by genetic differences. This nuanced understanding is critical in behavioral genetics, as it allows researchers to discern the roles of both nature (genetics) and nurture (environmental influences) in shaping behavior and characteristics. Other options may refer to related concepts but do not accurately define heritability. For instance, while environmental factors and upbringing are important for understanding behavior, they fall outside the narrow scope of heritability, which is strictly about the genetic contribution. Similarly, shared traits between siblings can stem from both genetic and environmental influences and do not solely capture the definition of heritability.