How many percents of having a small waist is due body fat%, and how many is due to genetic?

A guy here, I really love the wide big shoulder and a small waist look. And I wanna ask do I only need to have a low body fat % to get a small waist. Like, is it all body fat or, mainly genetic? Or both, then how many percents? 50-50? Would my waist look exactly the same as someone else' waist if at the same body fat %?