Age and IQ at intake as predictors of placement for young children with autism: a four- to six-year follow-up.
Starting intensive ABA before 42 months with IQ above 70 gives the best shot at regular-education placement, but older or lower-IQ kids still benefit.
01Research in Context
What this study did
The team tracked children with autism who entered an intensive ABA program at the Douglass Center. They recorded each child’s age and IQ at intake. Four to six years later they noted who was placed in regular-education classrooms.
No control group was used. The goal was to see which early signs predicted later school placement.
What they found
Kids who started before 42 months and had an IQ above 70 were far more likely to end up in regular-education classes. Older children or those with lower IQ still made IQ gains, but most stayed in special-education settings.
How this fits with other research
Rodgers et al. (2021) pooled 491 preschoolers and found small-to-medium IQ and adaptive gains after two years of intensive ABA. Their meta-analysis includes the present study, showing the same pattern: early start helps, yet results vary.
Jackson et al. (2025) repeated the placement check in a everyday clinic. They again saw that children who finished the full program mostly entered general-education, matching the 2000 result.
Eldevik et al. (2006) cut the dose to 12 hours a week and saw only small gains. This extends the 2000 finding: intensity matters; low hours do not close the gap.
Why it matters
If you run an early-intake clinic, screen children as soon as red flags appear. Aim to begin intensive ABA before 42 months, and keep hours high. For children who start later or score below 70, stay hopeful—keep the program strong and track smaller-step gains. Use the baseline IQ and age data when you explain realistic placement goals to families and school teams.
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02At a glance
03Original abstract
The predictive power of age and IQ at time of admission to an intensive treatment program using applied behavior analysis were examined in a 4- to 6-year follow-up of educational placement. Twenty-seven children with autistic disorder who were between the ages of 31 and 65 months and had IQs on the Stanford Binet between 35 and 109 at time of admission to the Douglass Developmental Disabilities Center were followed up 4 to 6 years after they left the preschool. The results showed that having a higher IQ at intake (M = 78) and being of younger age (M = 42 months) were both predictive of being in a regular education class after discharge, whereas having a lower IQ (M = 46) and being older at intake (M = 54 months) were closely related to placement in a special education classroom. The results are interpreted as pointing to the need for very early intervention for children with Autistic Disorder. It is also emphasized that older children and those with lower IQs in the present study showed measurable gains in IQ from treatment. The data should not be taken to suggest that children older than 4 years of age do not merit high quality treatment.
Journal of autism and developmental disorders, 2000 · doi:10.1023/a:1005459606120