Valence and Intensity of Emotional Expression in Autistic and Non-Autistic Toddlers

Differences in emotional experience and expression have long been recognized as common in the presentation of autism, yet research examining emotional expression in early childhood is limited, with mixed findings. Understanding emotional reactivity and expression in autism in early life is an essential step towards uncovering the mechanisms of these risks and identifying targets for intervention.

The present study examined emotional expression in autistic (N = 17) and non-autistic (N = 20) toddlers (mean age = 25.27; SD = 1.88) during emotion elicitation tasks aimed at eliciting joy, frustration, and unease. Video recorded tasks were coded in ten second intervals for emotional valence and intensity, and the following variables were computed: proportion of time in positive, neutral, and negative affect; maximum intensity of positive and negative affect; and range of affect (i.e., most negative to most positive intensity).

Autistic toddlers spent more time in neutral facial expressions, less time displaying positive affect, and had somewhat less intense positive emotional expression than non-autistic peers. Small differences were apparent in intensity of negative affect expression, while no differences emerged in duration of time spent in negative affect.

Findings emphasize that differences may be more apparent in duration, rather than intensity of emotional expression, and that it may be particularly important to examine periods of "neutral" affect in young autistic children. Future research should consider the best ways to understand emotional reactivity in this population considering their unique interests, challenges, and communication styles.