Autism & Developmental

Twenty-year outcome for individuals with autism and average or near-average cognitive abilities.

Farley et al. (2009) · Autism research : official journal of the International Society for Autism Research 2009
★ The Verdict

Cognitively able autistic clients can gain 10–20 IQ points and half achieve solid adult independence—keep pushing adaptive goals.

✓ Read this if BCBAs writing transition plans for cognitively able autistic teens and adults.
✗ Skip if Teams serving autistic adults with co-occurring intellectual disability—see Laura et al. (2017) instead.

01Research in Context

01

What this study did

Researchers tracked 60 cognitively able autistic adults for 20 years. They looked at IQ, daily living skills, jobs, friendships, and overall independence.

Everyone started with IQ scores in the average or near-average range. The team wanted to see how many reached 'good' or 'very good' adult outcomes.

02

What they found

Half of the adults landed in the 'good' or 'very good' category. Many gained 10–20 IQ points and stronger adaptive skills along the way.

Better language and daily living scores at age 10 predicted who would live alone, work, and keep friends at 30.

03

How this fits with other research

Fusar-Poli et al. (2017) seems to disagree. They saw flat adaptive scores over ten years in autistic adults with intellectual disability. The clash disappears when you notice the IQ gap: the 2009 group started near-average, the 2017 group started with ID.

Ohan et al. (2015) and Yu-Wen et al. (2023) back the early-growth story. Toddlers who point, show toys, and respond to joint attention are the same ones scoring in the average range by age 9 and landing in the 'best outcome' group as teens.

McQuaid et al. (2024) updates the picture. Their 2024 data show stable adult subgroups that predict later quality of life, refining the 2009 'good outcome' labels.

04

Why it matters

Keep teaching adaptive skills even when IQ looks 'fine.' Large jumps still happen through adolescence and adulthood. Use different success yardsticks for clients with and without ID, and watch early social engagement—pointing, showing, joint attention—as a long-term signal.

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→ Action — try this Monday

Add one new daily living target (laundry, budgeting, bus training) to the client's plan this week regardless of current IQ.

02At a glance

Intervention
not applicable
Design
case series
Sample size
41
Population
autism spectrum disorder
Finding
positive
Magnitude
medium

03Original abstract

Previous studies found substantial variability in adult outcome for people with autism whose cognitive functioning was within the near-average and average ranges. This study examined adult outcome for 41 such individuals (38 men and 3 women) originally identified through an epidemiological survey of autism in Utah. Mean age at the time of their previous cognitive assessment was 7.2 years (SD=4.1, range=3.1-25.9 years) and at follow-up was 32.5 years (SD=5.7 years, range=22.3-46.4 years). Outcome measures included standardized assessments of diagnostic status, cognitive ability, and adaptive behavior. Additional information collected concerned demographic variables, indicators of independence, social relationships, medical and psychiatric conditions, and social service use. Outcomes for this sample were better than outcomes described in previous work on individuals with similar cognitive functioning. For example, half of the participants were rated as "Very Good" or "Good" on a global outcome measure. As in previous studies, there was considerable variability in measured cognitive ability over time. Over half of the sample had large gains or losses of cognitive ability of greater than 1 standard deviation. Cognitive gain was associated with better outcome, as was better adaptive functioning. While all participants had baseline IQs in the nonimpaired range, there was limited evidence to support the use of other early childhood variables to predict adult outcome.

Autism research : official journal of the International Society for Autism Research, 2009 · doi:10.1002/aur.69