It’s not just cognitive. We lose taste buds with age, and the ones that remain shrink and lose sensitivity.

It makes sense if you think about it. Bitterness is associated with a lot of poisons. Sourness is associated with spoiled foods. Having a strong aversion to these tastes during childhood compelled our ancestors to avoid dangerous foods during their most fragile stages of life.

Then of course, sugar is a quick source of energy. It should be a given why a quick source of energy benefitted our ancient ancestors (for whom food was much more scarce.)

In short, that increased childhood sensitivity allowed our ancestors to survive until adulthood.

So parents - next time a kid complains about their dinner being too bitter, take comfort in knowing that if they were ever exposed to actual poison, they’d avoid it with the same urgency.