Well, your link lists concepts like "Five" or "Justice" as abstract, so the entire concept of "overweightness" instead of just "overweight child" is "abstract"

Well, your link lists concepts like "Five" or "Justice" as abstract, so the entire concept of "overweightness" instead of just "overweight child" is "abstract" by that measure. I guess I assumed you meant something more meaningful and less pedantic. And I don't think there's much of a leap in terms of abstraction if you just jump from "compared to the other kids, my kid is ok" to "compared to this number on a chart, my kid is ok". That is just a change in what data point you prefer to reference, not a change in thought patterns.