Twelve-month-old infants tended to look longer when the ball went to sit beside the “mean” shape. Perhaps they found the ball’s choice surprising. Would you choose to hang out with someone who had pushed you down a hill?

Similarly, children growing up in deeply religious Mennonite communities distinguish between rules that apply because they are written in the Bible (e.g., that Sunday is the day of Sabbath, or that a man must uncover his head to pray) and rules that would still apply even if they weren’t actually written in the Bible (including rules against personal and material harm).

while the “moral instinct” was apparently universal, people’s subsequent justifications were not; instead, they were highly variable and often confused. Less than one in three participants could come up with a justification for the moral difference between Camilla’s choice and Bob’s, even though almost everyone shares the intuition that the two cases are different.