Heritability vs. Inheritable — What's the Difference?

Heritability is a statistical concept that quantifies the proportion of observed variation in a particular trait among individuals in a population that can be attributed to genetic differences. It does not apply to an individual but rather to variations within a group. Inheritable, on the other hand, refers to any trait or characteristic that can be passed down from one generation to the next through genes. It's a broader term that includes anything that can be inherited, not just traits subject to genetic variation.

While heritability is a measure used primarily in the field of genetics and is particularly important in studies of human behavior, animal breeding, and plant cultivation, indicating how much of the variation in a trait can be attributed to genetic factors, inheritable traits include both genetic characteristics and other hereditary factors. These could range from genetic disorders to physical characteristics and even some social and cultural attributes that are passed down through family lines.

Heritability estimates do not provide information about how a trait can be passed from parent to offspring, nor do they indicate the degree to which an individual's traits are determined by genetics versus environment. Instead, they offer insights into the relative contributions of genetics and environment to the variation of traits in a population. Inheritable traits, however, are specifically those aspects of an organism that are directly transmitted from parents to their offspring, potentially including both genetic and non-genetic elements, such as cultural heritage or family traditions.

The concept of heritability is often misunderstood; a high heritability does not mean that environment has little effect on the development of a trait, nor does it imply that the trait cannot be changed. It simply means that within the studied population, a larger portion of the variation of the trait is due to genetic differences. Inheritable traits, while directly passed down from parents to offspring, can also be influenced by external factors. For example, a child might inherit a predisposition to a certain condition, but environmental factors such as diet and exercise can influence whether or not the condition manifests.

Understanding heritability is crucial for genetic research and breeding programs, as it helps scientists and breeders determine which traits are most likely to be passed down and how they can be selected for or against. On the other hand, understanding which traits are inheritable is important not only for genetic counseling and predicting health risks but also for appreciating the role of genetics in shaping individual and familial identities. Both concepts are integral to genetics, but they address different aspects of how traits are transmitted and expressed across generations.