Brief report: significant differences in perceived odor pleasantness found in children with ASD.

Hrdlicka et al. (2011) asked kids to sniff two common food smells: cinnamon and pineapple.

The team compared children with autism to same-age peers without autism.

Each child rated how nice the smell felt on a simple scale.

Children with autism gave lower "nice" scores to both smells.

The difference was large enough to reach statistical significance.

This hints that the kids noses worked fine, yet the pleasant feeling was muted.

Bao et al. (2017) later pooled 14 papers and saw mixed results across odor tests. They explain that smell identification problems show up more often than simple detection problems, helping us trust the current pleasantness gap.

Luisier et al. (2019) took the finding a step further. They exposed autistic children to a once-neutral food smell for five weeks. Sixty-eight percent of the kids later picked a food carrying that smell, proving that repeated exposure can lift the low pleasantness reported in 2011.

Legiša et al. (2013) looked at faces, heart rate, and self-ratings while kids smelled odors. Autistic children showed the same facial and body reactions as peers, but their words did not match their faces. The 2011 pleasantness scores therefore capture a labeling or reporting gap, not a broken nose.

When you choose edible reinforcers, remember that cinnamon candy or pineapple chunks may smell less inviting to some autistic learners. Offer a sniff test first, or pick a neutral-to-positive odor from the childs history. If the learner rejects the item, try brief daily exposure sessions; Luisier et al. (2019) show liking can grow in about a month.