When I hear things like this, my first thought is "define abuse." Is it a spanking? A cousin being inappropriate? Is it years of molestation? Is it being yelled at over and over while growing up? It seems more of an anecdotal observation than real evidence if it is not fully defined.
But I am not saying it is false either. I could see reasons why they would be correlated. For example, if someone is sexually abused, normal relationships may not seem so normal and they may be more willing to be less tied to social norms. Or maybe if someone were abused, they rather spread out their love than to put all their love in one proverbial basket.