By the age of three months, however, research has found that babies start to favor faces of their family’s race and ethnicity. A process that researchers call perceptual narrowing begins to blur faces that are different from those within the infant’s small, trusted circle. As a result, babies start to view members of other races as indistinguishable from one another, even as they become more closely attuned to the nuances and subtle signals from the people who are closest and most familiar to them—the people the child most depends on.
