Ga-ga, goo-goo, why a baby likes you

"Persistent discrimination and conflict across cultures has led psychologists to question whether we are naturally inclined to like people who are similar to ourselves and to dislike those who are different, or whether we are taught to feel this way," said Anthea Pun, the study's lead author and a graduate student in the UBC department of psychology. "These findings suggest both are true: liking people who are similar to ourselves seems to be an innate bias, but disliking those who are different is something we likely learn later."

Past research has found that, by the age of three, children show positive biases toward people who are similar to them and negative biases towards those who are different. In this study, the UBC researchers turned their attention to infants to determine when and how these biases first emerge.

They conducted six experiments involving 456 infants between the ages of eight months and 16 months at Science World's Living Lab located at TELUS World of Science in Vancouver. The experiments examined how quickly infants habituated to either familiar or unfamiliar language speakers performing prosocial (giving) behaviour or antisocial (taking) behaviour.

Habituation measures infants' rate of processing pictures and sounds presented to them. When the information is consistent with infants' expectations, attention declines at a faster rate. By measuring infants' rate of habituation, the researchers were able to independently measure whether infants had formed positive or negative evaluations of people speaking familiar and unfamiliar languages.

Across all experiments, the researchers found that, by one year of age, infants not only think of speakers of their native language as good, but they also expect them to be prosocial. The infants appeared to be surprised when observing speakers of their native language engaging in antisocial behaviour. Infants of this age, however, do not appear to have any positive or negative expectations of speakers of an unfamiliar language, suggesting that negativity toward groups different from their own is likely learned after the first year of life, the researchers found.

"This study provides critical insight into the origins of social group bias by allowing researchers to understand how positivity and negativity toward groups develops independently," said Andrew Baron, the study's senior author and associate professor in the UBC department of psychology.