There's No Denying Your DNA

Yesterday, we were driving in the van and I was handing snack-size cookies back to Eden by twos and having her pass one to Elly who sits too far for me to reach. I casually glanced into the rear view mirror in time to see Eden (on more than one occasion) take the cookies, check to see which one has more chocolate, and then hand the other one to Elly. How do I know she was checking for more chocolate? Well, let's just say it is hardwired into her maternal genetics.