Intellectual development in young children with autism spectrum disorders: A longitudinal study.
IQ in autistic preschoolers can dip, soar, or stall—family income and mom’s education predict who rises.
01Research in Context
What this study did
Peristeri et al. (2024) followed autistic and neurotypical preschoolers for four years. They gave IQ tests every year to see who went up, down, or stayed the same. They also asked about mom’s education and family money to see if those things mattered.
What they found
Some autistic kids lost points in non-verbal IQ. Others gained in verbal, non-verbal, or both. Typical kids mostly gained across the board. Kids whose moms had more school years and higher family income were the ones who climbed.
How this fits with other research
Emerson et al. (2007) first showed this split path: a few babies later labeled autistic already slid downhill while others held steady. Fecteau et al. (2003) saw autistic symptoms ease with age; Eleni now shows the same is true for some, but not all, IQ scores. Flapper et al. (2013) found receptive vocabulary grows slower in autistic boys; the new study says verbal IQ can still shoot up in some, so language is not doomed. Huguenin et al. (1980) saw daily skills improve even when IQ stayed flat; together the papers warn that one good score does not promise all areas will rise.
Why it matters
Expect anything. A low score today might jump next year, or the reverse. Always ask about parent school history and money before you label a child “low potential.” Use brief tests like the short Stanford-Binet when you must, but plan to retest because change is common.
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02At a glance
03Original abstract
Intelligence profiles in autism have been characterized by great variability. The questions of how autistic children's intelligence changes over time, and what factors influence these changes deserve study as part of efforts to document child autism profiles, but also because the relationship between intellectual functioning and children's background characteristics is poorly understood, particularly in a longitudinal context. A total of 39 autistic children and 39 age-matched neurotypical children (5-9 years old) completed two IQ assessments at preschool age and up to 4 years later. Repeated-measures analyses assessed longitudinal changes in the children's verbal (VIQ), performance (PIQ), and full-scale IQ (FSIQ) at group level. We further sought to identify clusters with distinct profiles in each group by adopting an unsupervised K-means clustering approach, and detect possible between-subgroup differences in terms of children's socioeconomic status and autism severity. The largest cluster in the autistic group was composed of children whose PIQ significantly dropped at follow-up, while the second largest cluster improved in all quotients; the smallest cluster, wherein children had more highly educated mothers than the rest of the clusters, was characterized by large improvement in VIQ. For the neurotypical children, there was a two-cluster division; the majority of them improved in the three quotients, while very few dropped in PIQ at follow-up. The relation between socioeconomic status and IQ changes was significant for both groups. The findings demonstrate both the complexity of intelligence changes in autism and the need to view this complexity through the lens of the children's socioeconomic diversity.
Autism research : official journal of the International Society for Autism Research, 2024 · doi:10.1002/aur.3089