Whoa. Programmed into our DNA, that's a pretty extraordinary claim. Consider feral children:
http://en.wikipedia.org/wiki/Feral_children#Reality
http://planetark.org/wen/53118
> "When carers leave the room, the girl jumps at the door and barks," the police said.
An extreme example I admit, but if it's preprogrammed into out DNA shouldn't she be "caring for things" instead?