Assessing intelligence at autism diagnosis: mission impossible? Testability and cognitive profile of autistic preschoolers.

Courchesne et al. (2019) asked a simple question: can we really measure IQ in minimally verbal preschoolers with autism at the moment of diagnosis?

They swapped the usual tests for ones that lean on visual strengths, like puzzles and picture tasks, instead of spoken questions.

The team then watched which kids could finish the new battery and how their scores compared to the old results.

More toddlers stayed in the testing chair when the tasks matched their strengths.

The new scores gave a fuller, brighter picture of each child’s true ability than the classic tools.

Magiati et al. (2001) already showed that picking Bayley versus Merrill-Palmer can shift a preschooler’s IQ by about 20 points. Valérie’s team moves that warning forward by showing which direction to go: choose strength-based items.

Mottron (2004) found that quick vocabulary tests like PPVT overestimate ability in older, high-functioning kids. The new study says the opposite danger—underestimation—hits minimally verbal three-year-olds when we stay with verbal-heavy kits.

Rodgers et al. (2021) pooled hundreds of kids and saw small-to-medium IQ gains after two years of intensive ABA. Accurate starting scores from Valérie’s method would make those gain calculations cleaner and fairer.

Your intake IQ sets the baseline for goals, funding, and parent expectations. If the first number is wrong, every later decision wobbles. Try a brief non-verbal scale—like Leiter-R or TONI—before you open the standard verbal kit. You will lose fewer kids to escape behavior and you will write truer treatment plans on day one.