Hmmm, looks like this is a half truth:
Cross-sensory interaction between gustatory and trigeminal nerves occurs in the anterior tongue. Surgical manipulations have demonstrated that the strength of this relationship varies across development. Capsaicin is a neurotoxin that affects fibers ...
pmc.ncbi.nlm.nih.gov
"Results
Reductions in taste bud volume occurred 50 days, but not 2 days post-treatment for rats treated as neonates. Adult rats at either time post-treatment were unaffected."
So there is actually some logic to not giving kids spicy food (at least not daily).
Which is funny when kids naturally hate hot peppers so much.
You learn something new every day:
"The use of ethanol as a capsaicin solvent is standard across both animal and human literature (e.g.,
Silver et al., 1985;
Pellicer et al., 1990;
McBurney et al., 1997) as capsaicin powder is water insoluble."
Put alcohol in your chili and it will be extra spicy!