If the kids really figured out the "better" rule, they should be able to accumulate more stars if the game runs longer. Given the study didn't choose to do tha

If the kids really figured out the "better" rule, they should be able to accumulate more stars if the game runs longer. Given the study didn't choose to do that, it's a dubious claim imo that the kids figured anything out at all. Likely they were just putting a bunch of blocks in the machine ad hoc.