Do not! I repeat, do not! upset the baby!
A study from the University of British Columbia's Centre for Infant Cognition found that babies have a bit of a mean streak when they meet people they perceive as different.
During the course of the experiment, babies were given a choice of snacks (either graham crackers or green beans). Then, researchers conducted a puppet show for the babies (aged 9 or 14 months old). The first puppet ate the same snack that the baby chose and the other puppet ate the other snack. Puppet 1 (who ate the same snack as baby), either acted indifferent, friendly or aggressively toward Puppet 2 (who ate the other snack).
From the puppet show, researchers found that when babies are given a choice of which puppet to play with following the puppet show, "almost all the infants at both ages preferred the character who harmed the dissimilar puppet over the character who helped him." One of the researchers, Kiley Hamlin said, "The fact that infants show these social biases before they can even speak suggests that the biases aren’t solely the result of experiencing a divided social world, but are based in part on basic aspects of human social evaluation."
While researchers were not able to peg the reason behind the babies' choices, Hamlin believes, "Infants might experience something like schadenfreude at the suffering of an individual they dislike. Or perhaps they recognize the alliances that are implied by social interactions, identifying an ‘enemy of their enemy’ (i.e., the harmer of a dissimilar puppet) as their friend."
One things for sure — don't be the person to disagree with baby!
Have you ever seen your baby be mean?