Marshall and Joe are brothers. Both are very interested in board games and both are very intellectual. Marshall is very kind and caring while Joe is a bit of a nerd. What is the role that genetics has likely played in the personalities of the two brothers?

Answer: There's an even split between genetics and life experience: both have shaped them.

Explanation:

Although personality traits are largely defined by our genetic composition, that's not the only element to be examined. Personality is not determined by a single gene, but rather by the actions of many genes working together. Furthermore, both genetic factors and environmental circumstances are key elements in building our personality. Having a specific model of genes doesn't inevitably develop a distinct trait, because some traits may happen solely in some settings.