I see no such an argument in the article. It is modern psychology, it tries to avoid judgements like "good" or "bad", it doesn't try to prove that kids are dumb (or geniuses), it tries to learn how it is. The core principle can be expressed roughly "people acts the best possible way until proven otherwise". It is like an axiom, though it lacks a mathematical rigor. So this article points to an another direction: while it is beneficial for children to sacrifice material rewards in exchange for better learning, for adults it is more beneficial to concentrate on the rewards. This difference causes them to employ different strategies shown in the experiment. Though this last sentence is not proven by the experiment, there may be other causes, but Gopnik did a lot of research pointing to the same direction: babies and kids are optimized for the learning.

From this follows a practically helpful advice: if you cannot understand your kid's behavior, try to find what she/he is trying to learn by doing what is she/he doing. For example, you told her not to open a cupboard, you know she learned the rule "do not open the cupboard", but now she opens it while looking you in the eye? ("terrible twos" may do this) She is trying to learn how would you react to her misbehavior, and what the best way to deal with it. So you'd better get a grip on yourself, turn on your inner teacher and show her exemplary reaction to misbehavior, which she may adopt later herself against other people breaking rules. She needs to explore the role of a rule breaker to learn how to deal with the rule breaking from both sides, so let her play that role by playing the role of a rule enforcer.

> The question then is - could they set this up such that kids actually perform better than adults?

Probably they can, but what the point of such an experiment? To prove that a strategy stressing learning can give more material rewards when compared to a strategy maximizing material rewards? It is not a psychology per se, it is more like a research of different strategies of a decision making, so it would be better if such a research was done by an AI-researcher.