A study published in Psychological Science found that infants as young as nine months old prefer individuals who harm people they perceive as different.
University of British Columbia researchers put on puppet shows for nine- and 14-month old infants, who watched two puppets choose between a snack that appealed to the babies and a snack that didn't.
The infants then watched a show in which a third puppet helped or harmed the puppets similar or dissimilar to them.
The study found that "almost all of the infants at both ages" chose to play with the puppet that "harmed" the puppet with dissimilar interests.
"Infants’ preference for those who harmed dissimilar others was just as strong as their preference for those who helped similar ones," the study said.
Researchers found that babies actually like watching people get hurt -- we might call it schadenfreude.
“Infants might experience something like schadenfreude at the suffering of an individual they dislike,” psychological scientist Kiley Hamlin said of the results. “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.”