So maybe the Maya children are more attentive in the origami/toy experiment — not because they have better attention spans — but because they are more motivated to pay attention. Their parents have somehow motivated them to pay attention even without being told.
They say maybe... I can think of other reasons why Maya children seem to be more interested in anything happening in a western lab, than western kids. I don’t know the details because I haven’t read the original paper, but reading the article I’m not sure this effect has been ruled out.