One of the great joys of my job is that you spend a huge amount of time investigating different areas of literature.
To be trained in karate is something because karate is a vicious thing. If you are any good at it, you can kill somebody with it. It is a vicious way to fight.
I align myself with almost all researchers in assuming that anything we do is a composite of whatever genetic limitations were given to us by our parents and whatever kinds of environmental opportunities are available.