Heritability

Synonyms

H²

Definition

Heritability is the proportion of phenotypic variance among individuals that can be attributed to genetic variance in a population. For a given trait (or phenotype) such as eye color, a researcher might wish to know how much of the total variance in the population is due to genetic causes. This variance, heritability (or h²), is calculated by dividing genetic variance by phenotypic variance:

$$ {h}^2=\mathrm{Vg}/\mathrm{Vp} $$

Scientists now know that numerous behavioral and cognitive phenotypes have a considerable genetic component. These include intelligence, information processing speed, memory, attention, and problem-solving; language and reading impairments, as well as clinical disorders, such as Huntington’s disease, schizophrenia, dementia, affective disorders, attention deficit hyperactivity disorder, and autism.

Cross-References

• Attention

• Intelligence

• Phenotype

• Processing Speed Index

• Reading