Sure. Tolerance builds up over extended use, so that’s one avenue. Another is knowing what causes bodily sensations. High caffeine for example can easily to ner

Sure. Tolerance builds up over extended use, so that’s one avenue. Another is knowing what causes bodily sensations. High caffeine for example can easily to nervousness if participants don’t know they got caffeine. Drugs like Ritalin can cause euphoria the first couple of times you use it. Ever drank alcohol? You have to learn to deal with that, the first time you’re drunk you are very different from the second time. And then we have the fact that they took random new puzzles; you study stuff you’ve already gone over in class, and study in a way you like. Please don’t buy into any psychological research; there is a reason more than 2/3rd of all their research cannot even be replicated.