People in different cultures eat different things, and within a culture, what you eat can signal something about who you are. But when the babies saw the second person do something less expected — when this second person instead hated this same food that the first person loved — the babies looked much longer. But if the two people acted as if they were enemies, or if they spoke two different languages, babies expected that they would prefer two different foods. Babies from monolingual English-speaking homes saw language as a marker of different cultures; as noted above, if two people spoke two different languages, babies expected that they would prefer two different foods. Infants are not just learning to eat the foods they are given; they are also learning by watching adults eat, and figuring out who eats what foods with whom.

Source: New York Times August 19, 2016 20:09 UTC