I agree that it's worth investigating...I was just expecting more detailed analysis from an academic paper. The story linked basically says "3-5 year-olds can classify stuff into groups."
For what it's worth, I have a 2- and 5-year-old, so I'd love to know more about how their brains are developing.
It sounds like the author effectively spent a day at a children’s museum grocery exhibit and wrote a paper about it.
Is there more to the underlying paper than the summary suggests?
Anyone who has watched a 4-year-old for any length of time would conclude that at least some of them are capable of classification.