Good question. I am myself leaning towards that society has by far the greatest impact in either case - but how much if we were to determine it in 1/100's...? I have no idea.
I don't think asking people is the answer because they wouldn't know. They'd only know what they think they know.
If we could measure in some way how much impact biology has, we may be able to give an educated guess. But then, on the other hand, our interpretation of what constitutes 'biology' is subjective and decided by 'society'
So we're back to square one.