Varieties of repetitive behavior in autism: comparisons to mental retardation.
Repetitive behaviors are heavier and more varied in autism than in mental retardation alone, and later work shows they split into sensory-motor and sameness factors you can measure with standard tools.
01Research in Context
What this study did
Donahoe et al. (2000) compared kids who had autism with kids who had mental retardation only.
They looked at how often and how severe each group showed hand flapping, rocking, lining up toys, and self-biting.
Parents answered questions; the team scored the type and strength of every repetitive behavior.
What they found
The autism group had more kinds of repetitive acts and the acts were stronger.
Stereotypy, compulsions, and self-injury all stood out in autism, not in mental retardation alone.
This backed the idea that odd, repeated movements are a core autism sign, not just low IQ.
How this fits with other research
Richler et al. (2007) later saw the same split in toddlers. Two-year-olds with autism already showed more sensorimotor repetition than kids with other delays, proving the gap starts early.
Matson et al. (2013) went bigger. They ran numbers on 1,825 children and locked in two clear RRB camps: sensory-motor and insistence-on-sameness. Their factor map updated the 2000 picture from "more severe" to "two separate tracks.
Scahill et al. (2015) stepped back and asked which tools best capture these tracks. They flagged five scales, including the ADI-R used in the 2000 paper, as trial-ready endpoints. So the same measure that first showed the autism spike is now a gold-standard yardstick.
Why it matters
If a client shows lots of movement repetition plus self-hit, think autism first, not just ID.
Use the two-factor lens when you write your assessment: note sensory-motor acts apart from sameness rituals.
Pick one of the five trial-ready tools, track the topographies you see today, and you will have baseline data that future reviewers will trust.
Want CEUs on This Topic?
The ABA Clubhouse has 60+ free CEUs — live every Wednesday. Ethics, supervision & clinical topics.
Join Free →Open your current autism file, list each repetitive act under sensory-motor or insistence-on-sameness, then pick the RBS-R or ADI-R to score baseline severity.
02At a glance
03Original abstract
Systematic study of abnormal repetitive behaviors in autism has been lacking despite the diagnostic significance of such behavior. The occurrence of specific topographies of repetitive behaviors as well as their severity was assessed in individuals with mental retardation with and without autism. The occurrence of each behavior category, except dyskinesias, was higher in the autism group and autistic subjects exhibited a significantly greater number of topographies of stereotypy and compulsions. Both groups had significant patterns of repetitive behavior co-occurrence. Autistic subjects had significantly greater severity ratings for compulsions, stereotypy, and self-injury. Repetitive behavior severity also predicted severity of autism. Although abnormal repetition is not specific to autism, an elevated pattern of occurrence and severity appears to characterize the disorder.
Journal of autism and developmental disorders, 2000 · doi:10.1023/a:1005596502855