Autism & Developmental

Random number generation in autism.

Williams et al. (2002) · Journal of autism and developmental disorders 2002
★ The Verdict

Low-functioning clients with autism may repeat responses more often — plan tasks that build variety and allow extra think time.

✓ Read this if BCBAs writing skill-acquisition programs for teens or adults with both autism and intellectual disability.
✗ Skip if Clinicians who only serve high-functioning verbal clients or focus on early childhood.

01Research in Context

01

What this study did

Researchers asked adults with low-functioning autism to say random numbers. They counted how often each person repeated the same digit. The task checks if someone can stop themselves from using a habit.

A control group did the same thing. The team compared the two sets of scores.

02

What they found

The autism group repeated digits far more often. This shows weaker response inhibition — the skill that keeps you from giving the same answer over and over.

The result fits the idea that executive functions can be uneven in autism.

03

How this fits with other research

Adams et al. (2021) now gives us the next chapter. Their larger study across all ages says the real problem is proactive control — slowing down before you act — not the sudden stop itself. The 2002 paper is still useful, but the mechanism has been refined.

Early et al. (2012) adds a twist. Kids with autism could stop a prepotent response just fine, yet they were tripped up by extra visual clutter. This tells us inhibition is not one thing; different parts may be weak or strong.

Walley et al. (2005) looks like a contradiction at first. After they held language and attention scores constant, the inhibition deficit disappeared. It reminds us to check receptive language and attention before calling a behavior an autism problem.

04

Why it matters

When you write a program that asks for varied responses — choosing different pictures, saying new words, rotating play actions — build in supports. Give extra wait time, cut visual noise, and probe language skills first. These small shifts honor the inhibition profile shown since 2002 and refined by newer work.

Free CEUs

Want CEUs on This Topic?

The ABA Clubhouse has 60+ free CEUs — live every Wednesday. Ethics, supervision & clinical topics.

Join Free →
→ Action — try this Monday

Insert a 2-second delay cue before any response you want to be non-repetitive.

02At a glance

Intervention
not applicable
Design
quasi experimental
Sample size
42
Population
autism spectrum disorder, intellectual disability
Finding
negative

03Original abstract

This study explored the ability of individuals with autism to generate a unique series of digits. Fourteen low-functioning individuals with autism, 14 intellectually disabled individuals, and 14 postgraduate university students generated a series of pseudo-random digits. Individuals with autism were more likely to repeat previous digits than were either of the control groups. The normal control group, however, was less likely to attempt cycling through all digits before repeating. Accordingly, low-functioning individuals with autism may exhibit a short-fall in response inhibition. This finding supports the executive dysfunction theory of autism.

Journal of autism and developmental disorders, 2002 · doi:10.1023/a:1017904207328