The simplest and most useful answer is that heritability tells you the amount of variation that environmental factors don’t control*. Traits with very high heritability** are generally going to be worse targets for intervention than traits with low heritability.
*In the range of environments over which the data was collected. The heritability of a trait as measured in Somalia or North Korea may be much lower that as measured in America. You can interpret this as meaning that there is much more hope for useful intervention in Somalia or North Korea, although the practical difficulties may be considerable.
**Some relevant traits are nearly 100% heritable, unfortunately. This includes executive function, which governs working memory and impulse control. Any non-biochemical intervention aimed at improving these traits is unlikely to succeed.
The simplest and most useful answer is that heritability tells you the amount of variation that environmental factors don’t control*. Traits with very high heritability** are generally going to be worse targets for intervention than traits with low heritability.
*In the range of environments over which the data was collected. The heritability of a trait as measured in Somalia or North Korea may be much lower that as measured in America. You can interpret this as meaning that there is much more hope for useful intervention in Somalia or North Korea, although the practical difficulties may be considerable.
**Some relevant traits are nearly 100% heritable, unfortunately. This includes executive function, which governs working memory and impulse control. Any non-biochemical intervention aimed at improving these traits is unlikely to succeed.