Relations between fine motor skills and intelligence in typically developing children and children with attention deficit hyperactivity disorder

Background The embodied cognition hypothesis implies a close connection between motor and cognitive development. Evidence for these associations is accumulating, with some studies indicating stronger relations in clinical than typically developing samples. Aims The present study extends previous research and investigates relations between fine motor skills and intelligence in typically developing children (n = 139, 7–13 years) and same-aged children with attention deficit hyperactivity disorder (ADHD, n = 46). In line with previous findings, we hypothesized stronger relations in children with ADHD than in typically developing children. Methods and procedure Fine motor skills were assessed using the standardized Movement Assessment Battery for Children. Intelligence was measured with the standardized Wechsler Intelligence Scale for Children. Outcomes and results Regression analyses indicated significant relations between fine motor skills and full-scale IQ, perceptual reasoning, working memory, and processing speed. Moderation analyses identified stronger relations between fine motor skills and full-scale IQ, perceptual reasoning, and verbal comprehension in children with ADHD compared to typically developing children. Conclusions and implications Results suggest a close relation between fine motor skills and intelligence in children with and without ADHD, with children diagnosed with ADHD showing stronger relations. Findings support combined motor-cognitive interventions in treating children with ADHD.