I mean yeah, genes can have an impact. Someone who can eat dairy products without any problems is more likely to be a cheesemaker than someone who throws up after eating cheese. However, all the places where genes might make an impact the person will figure out for themselves, we won't need to analyze them to figure it out. It wasn't some secret allele that makes people predisposed to trail-guiding, it was a very obvious genetic difference that they dealt with themselves.