Infants’ responses to masked and unmasked smiling faces: A longitudinal investigation of social interaction during Covid-19

During the COVID-19 pandemic, face masks became an effective hygienic measure to reduce infection rates. Given the relevance of facial expressions for social interactions, the question arises how face masks affect early social interactions. The current longitudinal study investigated how covering parts of the face might impact infants’ responses to others’ emotional expressions. Infants who were born during the pandemic were examined at three measurement points at the age of 6, 10 and 14 months. After displaying a neutral facial expression an experimenter smiled at infants while either wearing a mask (mask condition) or not wearing a mask (no mask condition). Infants’ change in affect (i.e., negative, neutral, positive) from the neutral to the test phase (i.e., smiling experimenter) was evaluated. Results showed that at 6 and at 10 months infants’ behavior did not differ between conditions, whereas at 14 months infants were more likely to show a change from neutral/negative affect to positive affect in the no mask condition than in the mask condition. Moreover, at 14 months infants were less likely to respond positively to the experimenter’s smile (across conditions) than at 6 and at 10 months. These findings broaden our understanding of potential effects of mask wearing on the development of face processing and affective communication. Overall, they indicate a developmental trend according to which infants’ processing and response to others’ positive emotions becomes more selective and differentiated with increasing age.