Free will is the ability to act counter to your predispositions. However, if you don't recognize those predispositions, you are unlikely to consider acting against them.
So knowledge saves free will.
now I'm confused...
But I am predisposed to that... :o)
Actually though I cant vouch for this particular study.
I believe a great deal has alot to do with nature more than nuture.
I think for the most part it is commons sense... and simply takes observation.
In my own experience... my son had a condition(ADD) that is found to cluster in genetic lines... though no genetic link has been found.
After he died... a few years ago .. I discovered I had a grandson --his son.. ...who grew up estranged from the family and in an entirely different environment.. I have since met and got to know my grandson. He not only has ADD etc...but he has several other behaviorial similarities that are obviously genetic