This is a massive problem right across biology. When we talk about heritability people assume we mean causal genetics for some trait. What we actually mean is a

This is a massive problem right across biology. When we talk about heritability people assume we mean causal genetics for some trait. What we actually mean is all the genetic variation that is causal and all the genetic variation that is correlated (by chance) with the trait. The latter are effectively instrumental variables that are predictive but not causal.