Ground walking in humans is typically stable, symmetrical, characterized by smooth heel‐to‐toe ground contact. Previous studies on children with autism spectrum disorder (ASD) identified various gait abnormalities. However, they produced inconsistent findings, particularly for the occurrence of toe walking and gait symmetry between feet, owing to their reliance on retrospective reports, visual analysis of videos, or kinematic analysis of the gait. The present study examined gait functions in children with ASD using plantar pressure that quantified foot–ground interaction with high spatial and temporal resolutions. Fifty‐eight 4–6‐year‐old children with ASD (12 low‐functioning and 46 high‐functioning autism) and 28 age‐matched typically developed children walked straight 6 m at their preferred speed for 10 repetitions. We found that both ASD groups walked with more flat‐footed contact pattern, more left–right asymmetry, and larger step‐to‐step variability than their controls. Furthermore, these abnormal gait characteristics were related to social impairments measured by the Autism Spectrum Quotient and Social Responsive Scale, supporting a close association between impaired motor coordination and core symptoms of autism. Autism Res 2020, 13: 1215‐1226. © 2020 International Society for Autism Research, Wiley Periodicals, Inc.Lay SummaryWe examined gait functions among children with autism by measuring their foot plantar pressure during simple straight walking. Children with ASD walked with a characteristic foot‐ground contact pattern with inappropriate contact forces and large step‐to‐step variability when compared with their age‐matched controls. These walking abnormalities were dependent on their social impairments but independent from their intelligence, indicating a close relationship between atypical motor coordination and core symptoms of autism.

Individuals with autism spectrum disorders (ASD) have shown impaired performance in canonical and nonsocial working memory (WM). However, no study has investigated social WM and its early development. Using biological motion stimuli, our study assessed the development of social and nonsocial WM capacity among children with or without ASD across the age span between 4 and 6 (N = 150). While typically developing (TD) children show a rapid development from age 5 to 6, children with ASD showed a delayed development for both social and nonsocial WM capacity, reaching a significant group difference at age 6. Furthermore, we found a negative correlation between social (but not nonsocial) WM capacity and the severity of autistic symptoms among children with ASD. In contrast, there is a positive correlation between both types of WM capacity and intelligence among TD children but not among children with ASD. Our findings thus indicate that individuals with ASD miss the rapid development of WM capacity in early childhood and, particularly, their delayed social WM development might contribute to core symptoms that critically depend on social information processing.