Contrarians--Genetic?

 I've long experience with contrarians--my sister was one.  I lean that way myself.

I wonder whether it's genetic or cultural?  Do "tight" societies , presumably ones less welcoming of contrarians, have fewer, or any at all?  I'd assume there might be an evolutionary basis--seems as if the species could benefit by having a few around, just as it presumably benefits by having a few left handers around.  On the other hand, while I'm a confirmed right handers, I was able to train myself to use the mouse left-handed when I was getting carpal tunnel pains.