Emotional Expressivity in Toddlers With Autism Spectrum Disorder

There is a prevailing notion that children with autism spectrum disorder (ASD) exhibit intense negative and attenuated positive emotions, although the empirical evidence regarding their emotional expressiveness (EE) is limited. Given the importance of emotions in shaping social and cognitive development, we examined intensity and valence of EE and links between EE and autism severity and parent-reported temperament in ASD.

Toddlers (aged 21.2 months) with ASD (n = 43), developmental delay (DD, n = 16), and typical development (TD, n = 40) underwent standardized probes designed to induce anger, joy, and fear. Intensity of EE through facial and vocal channels were coded offline. Autism severity and temperament were quantified using the Autism Diagnostic Observation Schedule-2 (ADOS-2) and Early Childhood Behavior Questionnaire (ECBQ).

The ASD group exhibited less intense fear compared to both the DD and TD groups, more intense anger than DD but not TD, with no differences in joy intensity. All groups showed similar levels of incongruous negative EE. Intensity of fear and anger were not associated with severity of autism symptoms, but lower intensity of joy was related to greater autism severity. Expressed fear and joy were associated with temperament.

The study provides no support for a negative emotionality bias in ASD. Instead, toddlers with ASD display a muted response to threat and an accentuated response to goal blockage, whereas the ability to express positive emotions appears intact. Negative emotionality and social disability dimensions are independent. The study demonstrates the complexity of EE in ASD and motivates investigations into underlying mechanisms as well as its role in shaping complex phenotypes of affected children.