Babies Are Seekers of Justice
If you've ever taken a psychology class or watched Lost, you're probably familiar with the theory that people are born as blank slates. The idea is that we soak up ethics from our caregivers and environment, that we're born as morally ambiguous as a really good Breaking Bad episode. But recently, science has proven otherwise. Before we're able to talk or walk or take care of our own poops without sitting in them for a while first, we're able to distinguish between good and evil. Not only that, but we're also able to choose the right side. (Good ... the right side is good.)
Why else is "sinister" the Latin word for "left"?
Researchers at Yale stuck babies between 6 and 10 months old in front of a puppet show, a morality tale featuring anthropomorphic geometric shapes, which sounds like the shittiest puppet show ever. Basically it boiled down to a yellow triangle helping a red ball up a hill, while a blue square tried to push the red ball back down. All of these shapes had eyes, if that helps with your mental picture. The important part is that when given a choice on which shapes they preferred, 80 percent of the babies reached for the helper shape, as if to say "You are the best and I want you" (or possibly "You are the one I am going to eat because I too am evil," but probably that first one).
If you think that was just a coincidence (like maybe the helper shape was also shaped like a boob), they've done multiple versions of the study -- for instance, babies as young as 8 months agree that justice should be rewarded and evil should be punished. That study was again conducted with puppets (the universal language of babies), and in this one a bad puppet was either rewarded or punished as the babies watched. This time, the babies picked the punisher as their favorite. Not the victim or the bad guy, but the one who administered justice.
Dynamic Graphics Group/Dynamic Graphics
A baby who doesn't love Frank Castle isn't a baby we'd want to keep anyway.