Gross motor ability is associated with profound differences in how children experience and interact with their social world. A rapidly growing literature on motor development in autism spectrum disorder (ASD) indicates that autistic individuals exhibit impairment in gross motor skills. However, due to substantial heterogeneity across studies, it remains unclear which gross motor skills are impaired in ASD, when and for whom these differences emerge, and whether motor and social impairments are related. The present article addressed these questions by synthesizing research on gross motor skills in ASD in two separate meta-analyses. The first examined gross motor deficits in ASD compared to neurotypical (NT) controls, aggregating data from 114 studies representing 6,423 autistic and 2,941 NT individuals. Results demonstrated a significant overall deficit in gross motor skills in ASD (Hedges' g = −1.04) that was robust to methodological and phenotypic variation and was significant at every level of the tested moderators. However, moderation analyses revealed that this deficit was most pronounced for object control skills (i.e., ball skills), clinical assessment measures, and movements of the upper extremities or the whole body. The second meta-analysis investigated whether gross motor and social skills are related in ASD, synthesizing data from 21 studies representing 654 autistic individuals. Findings revealed a modest but significant overall correlation between gross motor and social skills in ASD (r = 0.27). Collectively, results support the conclusion that motor deficits are tied to the core symptoms of ASD. Further research is needed to test the causality and directionality of this relationship. Public Significance StatementThese meta-analyses reveal that individuals on the autism spectrum exhibit a large deficit in gross motor skills compared to neurotypical individuals, regardless of the individual's age, sex, or cognitive ability. Further, gross motor impairment is modestly associated with social impairment for autistic individuals.

Background Girls with autism spectrum condition (ASC) are chronically underdiagnosed compared to boys, which may be due to poorly understood sex differences in a variety of domains, including social interest and motivation. In this study, we use natural language processing to identify objective markers of social phenotype that are easily obtained from a brief conversation with a nonexpert. Methods 87 school‐aged children and adolescents with ASC (17 girls, 33 boys) or typical development (TD; 15 girls, 22 boys) were matched on age (mean = 11.35 years), IQ estimates (mean = 107), and – for ASC participants – level of social impairment. Participants engaged in an informal 5‐min ‘get to know you’ conversation with a nonexpert conversation partner. To measure attention to social groups, we analyzed first‐person plural pronoun variants (e.g., ‘we’ and ‘us’) and third‐person plural pronoun variants (e.g., ‘they’ and ‘them’). Results Consistent with prior research suggesting greater social motivation in autistic girls, autistic girls talked more about social groups than did ASC boys. Compared to TD girls, autistic girls demonstrated atypically heightened discussion of groups they were not a part of (‘they’, ‘them’), indicating potential awareness of social exclusion. Pronoun use predicted individual differences in the social phenotypes of autistic girls. Conclusions Relatively heightened but atypical social group focus is evident in autistic girls during spontaneous conversation, which contrasts with patterns observed in autistic boys and TD girls. Quantifying subtle linguistic differences in verbally fluent autistic girls is an important step toward improved identification and support for this understudied sector of the autism spectrum.

Background: Individuals with autism spectrum disorder (ASD) are characterized by social communication challenges and repetitive behaviors that may be quickly detected by experts (Autism Res 10:653-62, 2017; American Psychiatric Association, Diagnostic and statistical manual of mental disorders, 2013). Recent research suggests that even naïve non-experts judge a variety of human dimensions using narrow windows of experience called "first impressions." Growing recognition of sex differences in a variety of observable behaviors in ASD, combined with research showing that some autistic girls and women may "camouflage" outward symptoms, suggests it may be more difficult for naïve conversation partners to detect ASD symptoms in girls. Here, we explore the first impressions made by boys and girls with ASD and typically developing (TD) peers. Methods: Ninety-three school-aged children with ASD or TD were matched on IQ; autistic girls and boys were additionally matched on autism symptom severity using the ADOS-2. Participants completed a 5-minute "get-toknow-you" conversation with a new young adult acquaintance. Immediately after the conversation, confederates rated participants on a variety of dimensions. Our primary analysis compared conversation ratings between groups (ASD boys, ASD girls, TD boys, TD girls). Results: Autistic girls were rated more positively than autistic boys by novel conversation partners (better perceived social communication ability), despite comparable autism symptom severity as rated by expert clinicians (equivalent true social communication ability). Boys with ASD were rated more negatively than typical boys and typical girls by novel conversation partners as well as expert clinicians. There was no significant difference in the first impressions made by autistic girls compared to typical girls during conversations with a novel conversation partner, but autistic girls were rated lower than typical girls by expert clinicians. Limitations: This study cannot speak to the ways in which first impressions may differ for younger children, adults, or individuals who are not verbally fluent; in addition, there were more autistic boys than girls in our sample, making it difficult to detect small effects. Conclusions: First impressions made during naturalistic conversations with non-expert conversation partners could-in combination with clinical ratings and parent report-shed light on the nature and effects of behavioral differences between girls and boys on the autism spectrum.