Contagious Positive Affective Responses to Laughter in Infancy
Emotional Contagion is the unconscious converging of one’s emotional state with another, suggesting that one can “catch” the emotions of another through vocal, postural, and facial expressions (Hatfield et al., 1993). This phenomenon can be observed in infancy as early as the first 24 hours following birth. While negative emotional contagion has been studied in the form of contagious crying at various ages of infancy, positive emotional contagion has received very little attention. The purpose of the present study was to observe the emotional reactions of infants at 5 and 10 months of age when presented with a stimulus of their peers displaying positive affect. We hypothesized that infants would react to the stimuli of positive emotions with expressions of positive affect, including laughter. Additionally, we hypothesized that the intensity and duration of both the facial and vocal expressions would increase with age between assessments at 5 and 10 months. Results indicated that infants responded with positive emotions to the positive emotional stimuli more often than neutral stimuli, but emotional responsiveness did not increase between the two ages of assessment. This occurrence provides an initial platform for exploration of positive affect in infancy and its development into early childhood.