That is an excellent article LisaRose thanks for posting that.
I think a lot of people struggle with the idea that behaviour is rooted in biology. There is a good example involving voles. In one species the males are good loyal attentive dads and in a closely related species the males are deadbeats who don't stay around after impregnating the female. Scientists identified a gene that they could manipulate to transform their behaviour.
It makes me wonder about free-will.