it may well be that there are genetic differences. but until we have proof and the ability to measure the difference, i also think that believing in talent being genetic is dangerous as it holds back people who are perceived to be untalented. if i believe that the talent of my kids is genetic then i will be less likely to try to foster them to do better. this is especially dangerous for teachers.
our society suffers a lot from believing that people are poor because they have no talent to do better. and worse some apply this based on race. we can talk about talent being genetic when we no longer have poor people and have abolished all racism, but until we have done everything we can to allow everyone to develop their talent, we risk misusing this belief as an excuse not to support people to do better because we lack the believe that they even could do better.