Babies Can Distinguish Friendly and Unfriendly Relationships, Study Suggests

New research on infant cognition suggests that well before they develop language skills or understand much about social structure, babies can infer whether a person is friendly based on the person's likes and dislikes.

The research, reported by the University of Chicago, suggests that infants as young as 9 months old can engage in the reasoning necessary to distinguish friends from foes.

"This is some of the first evidence that young infants are tracking other people's social relationships," said study co-author Amanda L. Woodward, a professor of psychology at University of Chicago.

Woodward and her colleagues published their research in the Journal of Experimental Psychology: General.

In the study, the researchers examined 64 9-month-old babies, placing them in random groups. The infants were shown videos of two adults. In the footage, the two adults each ate two foods and reacted in either a positive or negative way to each food they ate. In some of the scenarios, the adults shared the same reactions, while in others their reactions to the food were different.

"We depicted evaluations of food because food may provide particularly salient social information," said co-author and psychologist Katherine D. Kinzler. "Eating with family and friends is inherently social, and so infants might be particularly inclined to use eating behaviors to make inferences about social relationships."

Then, in an attempt to investigate whether infants linked social relationships to the filmed food reactions, the researchers showed the infants footage of the same adults acting either positively or negatively towards each other.

The positive reaction was scripted as a friendly "Hi" and a smile, while the negative reaction pantomimed by the adults featured crossed arms, a turned back and a disgruntled noise.

The researchers measured the infants' reactions to the positive and negative scenarios by assessing the amount of time the babies focused on each video. Previous research has indicated that the longer an infant gazes at something is related to how familiar or unexpected it seems to them.

"When babies see something unexpected, they look longer," Woodward said. "It's out of place for them, and they have to make sense of it."

Based on the observations, the researchers suggested that infants were surprised when adults who liked the same foods behaved negatively towards each other. The babies also gazed longer at scenarios where adults who disagreed about foods behaved like friends.

"This study raises questions on how babies think about who gets along and who doesn't," said lead author Zoe Liberman, a UChicago doctoral student in psychology. "Parents will be interested to know that babies are keeping track of what's going on in the world around them and are making inferences about social interactions that we previously were not aware of before this study."

"I was surprised to find that babies at this age showed such strong responses," Woodward said.