What if we postulate a general factor "b" that correlates with a superior body, is that inheritable? It's not that certain characteristics of the brain aren't i

What if we postulate a general factor "b" that correlates with a superior body, is that inheritable? It's not that certain characteristics of the brain aren't inheritable, it's that "intelligence" is very diffuse and hard to define. It's not even so clear that what many of us would call intelligence is mainly an evolutionary advantage, either.