The development of normal and autistic children: a comparative study.
Autistic development includes behaviors that never appear in typical kids, so watch for odd, not just late.
01Research in Context
What this study did
The team watched two groups of kids: autistic and neurotypical.
They used the BRIAAC checklist to score daily behaviors.
The goal was to see if autistic kids just lag behind or show odd behaviors never seen in typical growth.
What they found
Some autistic actions were simply delayed.
Other actions never show up in any normal stage.
The data say autism is not just slow development; parts of it are qualitatively deviant.
How this fits with other research
Green et al. (1987) ran a near-copy study one year later.
They added severely retarded non-autistic kids and found the same split, boosting confidence in the original pattern.
Siegel et al. (1986) moved the field forward in the same year.
Instead of watching kids, they tested three rating tools head-to-head and showed CARS gives the clearest split from intellectual disability.
Aikat et al. (2025) extends the idea into the iPad age.
An app now tracks gaze and motor moves to separate autistic from typical preschoolers, proving the core question still drives new tech.
Why it matters
When you assess, look for behaviors that are off the map, not just late.
If a skill feels odd for any age, flag it and pair it with a validated tool like CARS or the SenseToKnow app.
This mindset keeps you from brushing off red flags as mere delay.
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02At a glance
03Original abstract
This study tests the hypothesis that the development of normal and autistic children differs only in rate and asymptote. A total of 195 normal children between 1 and 5 years of age, 160 normal children between 3 months and 24 months of age, and 41 autistic children between 5 and 11 years of age were evaluated on the eight psychological variables constituting the Behavioral Rating Instrument for Autistic and other Atypical Children (BRIAAC). While many similarities were found, there were a sufficient number of differences to justify DMS-III's statement that certain autistic behaviors are not normal at any stage of development. Differences were particularly prominent when the development of normal infants was compared with that of severely disturbed autistic children. In general, the issue of whether deviant development differs only quantitatively from normal development can best be decided on the basis of developmental data and by utilizing instruments that sample all the major characteristics of both populations.
Journal of autism and developmental disorders, 1986 · doi:10.1007/BF01531662