What’s in a baby’s smile?

Watch a nine-month-old baby playing with his mother and it’s already apparent that the child is a truly social being. You’ll doubtless see him smiling and directing his mother’s attention to share what he’s interested in. But according to Meaghan Parlade and colleagues, not all babies at this age have equal social skills – subtle differences in their social behaviour can be discerned and are predictive of social and emotional adjustment eighteen months later.

One such behaviour that varies between babies is what the researchers call “anticipatory smiling” – the act of looking at an object, such as a toy, smiling, and then gazing at mum, dad, or some other social partner, with that smile still in place. By way of contrast, a “reactive smile” is where the baby looks at a toy, turns to their mum and smiles only after making eye contact. The “anticipatory smile” is deemed a more advance social skill because it reflects a motivation to engage others using positive emotion.

Parlade’s team videoed babies interacting with their care-givers when they were six, eight, ten, twelve and thirty months old. What they found was evidence of a clear developmental trajectory: babies at six months who smiled more at a suddenly unresponsive parent (a test known as the “still face” procedure) also tended to employ more “anticipatory smiles” between the age of eight and twelve months, and in turn, those babies who used more “anticipatory smiles” tended to be more socially competent at thirty months, as judged by such things as their ability to play well with other children and talk about feelings. By contrast, earlier use of “reactive smiles” did not have this association with later social competence.

“These associations suggest a line of continuity between infants’ emotional expressivity during early social situations and later adaptive relatedness with others,” the researchers said. “Anticipatory smiles may signify an awareness of the separate attentional state and affective availability of the other.”

ResearchBlogging.orgM PARLADE, D MESSINGER, C DELGADO, M KAISER, A VANHECKE, P MUNDY (2009). Anticipatory smiling: Linking early affective communication and social outcome. Infant Behavior and Development, 32 (1), 33-43 DOI: 10.1016/j.infbeh.2008.09.007

Post written by Christian Jarrett (@psych_writer) for the BPS Research Digest.