A categorical approach to infants' individual differencesduring the Still-Face paradigm

Cluster analysis was used to create patterns of individual differences reflecting infant behav-iors during the initial interaction episode of the Face-to-Face Still-Face (FFSF) paradigm. Theclusters were used as the basic unit of analysis for studying infant and maternal behavior anddyadic coordination (i.e., matching and reparation) across FFSF. Seventy-five 4-month-oldinfants participated with their mothers. Cluster analysis identified three patterns: a SociallyEngaged cluster (33%) exhibited high levels of social engagement with their mothers; a Dis-engaged cluster (60%) showed a tendency to be low in social interaction and a NegativelyEngaged cluster (7%) showed high negative emotionality. During the Still-Face episode,the Socially Engaged cluster reacted by reducing focus on their mother and shifting theirattention elsewhere, while infants in the Disengaged cluster reduced focus on the environ-ment. Although both the Socially Engaged and Disengaged clusters increased in negativeemotionality during the Still-Face, the Socially Engaged group largely recovered during theReunion, whereas the Disengaged group displayed more negative emotion. The NegativelyEngaged cluster demonstrated high levels of negative affect throughout the entire proce-dure. Mothers of Negatively Engaged infants showed less positive engagement and moresocial monitoring than mothers in other clusters during all episodes. Dyadic interactiondiffered between groups, with greater levels of matching and reparations in the engagedgroup, less in the Disengaged group, and very little coordination in the Negatively Engagedcluster. Findings highlight the role of distinctive patterns of infants' individual differencesin determining early dyadic functioning.