Which descriptor BEST differentiates autism spectrum disorder from developmental coordination disorder?

• A. Decreased muscle tone
• B. Impaired motor coordination
• C. Decreased participation in organized sports
• D. Restricted, repetitive behaviors

Answer: (D)

Distinguishing these conditions hinges on what features are unique to autism. Autism spectrum disorder includes restricted, repetitive patterns of behaviors, interests, or activities as part of its defining profile, along with social-communication differences. Developmental coordination disorder, on the other hand, centers on motor coordination difficulties and does not include those persistent repetitive behaviors.

So, while decreased muscle tone or impaired motor coordination can appear in various conditions, and participation in sports can be affected for many reasons, those factors aren’t specific to autism. The presence of restricted, repetitive behaviors is the standout feature that differentiates autism from developmental coordination disorder. For example, repetitive routines, insistence on sameness, or repetitive movements are characteristic of autism but not of DCD, which mainly involves clumsy or poorly coordinated motor skills without such behaviors.