Less frequent face looking in infancy is related to autism likelihood status but not diagnosis: A study of parent-infant interaction

Background: Previous research suggest that autistic children look less at faces than neurotypically developing children, but this finding is based predominantly on screen-based eye tracking studies, with unfamiliar faces used as stimuli. The aim of the current study was to assess 10-month-olds' gaze to faces in a more naturalistic context - during free play with a parent - in relation to later autism diagnosis. Method: Parents were asked to play with their infant 'as they usually would' with a set of toys on the floor. During the first 5 min of play, infant gaze to parent's face was video coded. Results: Infants at elevated likelihood of autism (N = 18 with later diagnosis; 46 without later diagnosis), regardless of later diagnostic status, produced fewer gaze shifts towards their parents' faces than infants at low likelihood of autism (N = 18). Infants in all groups spent only similar to 3 % of their time looking at parents' faces, and there was no group difference in terms of the proportion of time spent looking at faces. There was neither a correlation between infant face looking and scores on the Autism Diagnostic Observation Schedule-2, nor between infant face looking and autistic traits in the parent. Conclusions: During toy play, all infants - irrespective of later diagnosis - spent very little time looking at parents' faces. Infants at elevated likelihood of autism made fewer gazes to their parents' faces than neurotypically developing infants, which could potentially affect opportunities for social learning. The effect was not specifically linked to later autism diagnosis.