On the Developmental Trajectories of Relational Concepts Among Children and Adolescents With Intellectual Disability of Undifferentiated Etiology.

Facon et al. (2021) tracked how kids with intellectual disability learn relational words. These are words like "bigger," "before," or "same."

The team compared kids with ID to typically developing peers. They matched groups by nonverbal IQ, not by age.

Once nonverbal level was equal, both groups followed the same learning path. Kids with ID reached each concept milestone in the same order as TD kids.

The curve looked nearly identical. Timing, sequence, and shape did not differ between groups.

Drahota et al. (2008) saw the same pattern with illness concepts. When they matched by cognitive level, ID and TD kids looked alike. Bruno extends this idea to relational language.

van Wingerden et al. (2017) seems to disagree. They found big gaps in early reading skills between ID and TD groups. The gap stays even when IQ is similar. The difference is the skill tested: Evelien measured decoding, not concept order. Decoding needs extra print skills that concept learning does not.

Mashal et al. (2012) adds nuance. Kids with learning disabilities struggled with common idioms but kept up on fresh visual metaphors. Again, the task type decides whether you see a deficit.

You can use the same concept sequence charts for both ID and TD learners. Just check nonverbal IQ first, not birthday. If a client is stuck on "before/after," look at cognitive level, not calendar age. Match teaching examples to that level and move on. No need to invent a separate curriculum.