Delay of gratification: a comparison study of children with Down syndrome, moderate intellectual disability and typical development.
Preschoolers with Down syndrome wait half as long for rewards, and their language skill drives the difference.
01Research in Context
What this study did
The team gave the classic marshmallow test to the preschoolers. Thirty had Down syndrome, 30 had moderate intellectual disability, and 30 were typically developing.
Kids sat at a table with one candy in front of them. They were told if they waited they would get two candies. The adult left the room and the timer started.
What they found
Children with Down syndrome waited about half as long as the other two groups. Most gave in before five minutes.
Only the Down syndrome group showed a clear link between language skill and wait time. Better receptive vocabulary predicted longer waits.
How this fits with other research
Leezenbaum et al. (2019) ran the same task with preschoolers with autism. They also saw shorter waits and more staring at the treat. Together the two studies show delay problems are common across developmental disabilities, but the reasons differ.
Micai et al. (2021) pooled 38 inhibition studies in Down syndrome. Their meta-analysis backs the small, real deficit we see here.
Konke et al. (2026) flip the coin: they show stronger delay skills can protect adaptive skills in high-risk toddlers. The takeaway is clear—teaching kids to wait matters.
Why it matters
If you work with preschoolers who have Down syndrome, plan for short wait times and build in language cues. Use simple, concrete phrases like “first wait, then two.” Practice during snack, circle time, or transitions. Small daily reps can stretch self-control and boost adaptive behavior later.
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02At a glance
03Original abstract
BACKGROUND: Self-regulation has been found to be an important contributor to a range of outcomes, with delay of gratification (a self-regulatory skill) predicting better academic, social and personal functioning. There is some evidence that individuals with Down syndrome have difficulty with delay of gratification. We investigated the question of whether this difficulty is common to intellectual disability irrespective of aetiology, or whether it presents a particular problem for those with Down syndrome. The latter was considered a possibility because of language difficulties in this group. METHOD: Three groups of children with a mean MA between 36 and 60 months participated in the study: children with Down syndrome (n = 32), children with a moderate intellectual disability from a cause other than Down syndrome (n = 26) and typically developing children (n = 50). Children completed a series of measures of language and cognitive functioning and participated in a delay of gratification task. RESULTS: The group of children with Down syndrome delayed for a significantly shorter time than either of the other two groups that did not differ from each other. Receptive language was associated with delay time for the children with Down syndrome but not for the typically developing group, nor for the group with moderate intellectual disability. CONCLUSIONS: Children with Down syndrome appear to have a particular difficulty with delay of gratification. Language abilities would seem to be implicated in this difficulty, although further examination of this hypothesis is required.
Journal of intellectual disability research : JIDR, 2016 · doi:10.1111/jir.12262