2015
1. All human behavioral traits are heritable. [That is, they are affected to some degree by genetic variation.]
2. The effect of being raised in the same family is smaller than the effect of genes.
3. A substantial portion of the variation in complex human behavioral traits is not accounted for by the effects of genes or families.
4. A typical human behavioral trait is associated with very many genetic variants, each of which accounts for a very small percentage of the behavioral variability.2
The Fourth Law of Behavior Genetics - Christopher F. Chabris, James J. Lee, David Cesarini, Daniel J. Benjamin, David I. Laibson, 2015
https://journals.sagepub.com/doi/full/10.1177/0963721415580430