Just how soon babies can perceive specific features of their world is a hot topic among psychologists. A new study in this area has found that by 9 weeks of age, babies can learn to recognize and favor a new face in a matter of minutes (SN: 7/7/01, p. 10: Faces of Perception).
If calm infants spent a brief period–3 1/2 minutes, in this study–looking into the eyes of a smiling female stranger who also delivered a sweet-tasting drink or pacifier, they subsequently preferred looking at that person rather than another stranger. A pacifier dipped in sugar water yielded the strongest face preferences with 9-week-olds; squirts of a sucrose solution from a sterile syringe worked best with 12-week-olds.
“These data point to the centrality of eye [contact] in learning about faces and establishing facial preferences in 2- and 3-month-olds,” say Elliott M. Blass and Carol A. Camp, both psychologists at the University of Massachusetts at Amherst.
In crying babies, comparable eye contact with a stranger offering a sweet treat slowed the flow of tears but didn’t result in a subsequent preference for that person’s face, Blass and Camp report in the November Developmental Psychology.
The researchers studied 140 infants, all 9 weeks or 12 weeks old. Secured in a seat, each baby sat facing a female researcher who either gazed into the child’s eyes or looked above the infant’s forehead while delivering one of the two sweet offerings. Afterward, each mother held her baby so that the infant could look either at the researcher or at another female stranger.
If calm infants encountered a researcher who avoided making eye contact, they didn’t gravitate to that person’s face later on, even if the initial trial had included a sweet inducement. Most of these babies cried if they received a sweetened solution or pacifier without eye contact, the scientists note. If a researcher avoided eye contact and offered no sweets, infants repeatedly smiled, gurgled, and otherwise tried to capture her attention.
Given positive stimulation from others, which in real-life situations includes caressing and suckling, babies first learn to recognize eyes and their surrounding facial features, the scientists theorize.