Heritability

Heritability is a statistical concept that describes the proportion of observed variation in a particular trait, as it occurs in a specific population, that can be attributed to inherited genetic factors in contrast to environmental ones. Heritability is estimated from populations, not individuals, and it applies only to the population in which it was estimated.

Definition

Heritability is a measure of how well differences in people's genes account for differences in their traits. Traits can include characteristics such as height, eye color, and intelligence, as well as disorders like schizophrenia and autism spectrum disorder. In scientific terms, heritability is a statistical concept represented by a number between 0 and 1.

Calculation

Heritability is calculated by comparing the phenotypic variance of individuals with different degrees of relatedness. It is often estimated from twin studies, where the total variance is partitioned into additive genetic variance, non-additive genetic variance, shared environmental variance, and non-shared environmental variance.

Limitations

Heritability does not indicate what proportion of a trait is determined by genes and what proportion by environment. So a heritability of 0.7 does not mean that the trait is 70% "caused" by genes. It also does not tell us anything about the nature of the genetic and environmental factors at work.

See also

• Genetics
• Twin studies
• Phenotypic variance
• Environmental variance

Heritability

• Critique of the Theory of Evolution
  Critique of the Theory of Evolution
• 
  Additive and Dominance Effects
• Galton Experiment
  Galton Experiment
• Twin Concordances
  Twin Concordances
• Response to Selection
  Response to Selection