Wide vs Narrow heritability

Heritability measures how much of the variation in a trait within a group is due to genetic differences. Narrow heritability considers only the proportion of variation passed from parents to offspring through additive genes, which are genes that add up to influence traits—like height or intelligence. Wide heritability includes all genetic factors affecting the trait, such as gene interactions (dominance) and gene combinations (epistasis). Essentially, narrow heritability focuses on predictable, inheritable genetic effects, while wide heritability captures the total genetic influence, including more complex interactions.