But there’s been criticism of Mischel’s findings too—that his samples are too small or homogenous to support sweeping scientific conclusions and that the Marshmallow Test actually measures trust in authority, not what he says his grandmother called sitzfleisch, the ability to sit in a seat and reach a goal, despite obstacles. I met with Mischel in his Upper West Side home, where we discussed what the Marshmallow Test really captures, how schools can use his work to help problem students, why men like Tiger Woods and President Bill Clinton may have suffered “willpower fatigue”—and whether I should be concerned that my five-year old devoured “the marshmallow” (in his case, a small chocolate cupcake) in 30 seconds.

Jacoba Urist: I have to tell you right off, my son is in kindergarten and he flunked the Marshmallow Test last night.

Walter Mischel: First, it’s important that I say “the test” in quotes, because it didn’t start out as a “test” but a situation where we were studying the kinds of things that kids did naturally to make self-control easier or harder for them. Four-year-olds can be brilliantly imaginative about distracting themselves, turning their toes into piano keyboards, singing little songs, exploring their nasal orifices.

Urist: The problem is, I think he has no motivation for food. In our house, dessert isn’t a big deal. Could the kids who wait for the marshmallow just not care that much about treats? Maybe their families didn’t use food as a reward system so they didn’t respond to it as a motivator?

Mischel: You have to understand, in the studies we did, the marshmallows are not the ones presented in the media and on YouTube or on the cover of my book. They were these teeny, weeny pathetic miniature marshmallows or the difference between one tiny, little pretzel stick and two little pretzel sticks, less than an inch tall. It’s really not about candy. Many of the kids would bag their little treats to say, “Look what I did and how proud mom is going to be.” The studies are about achievement situations and what influences a child to reach his or her choice. In some cases, we even used two colored poker chips versus one.

Urist: How important is trust then? Some critics claim that a 2012 University of Rochester study calls the Marshmallow Test into question. Children in a reliable environment (where they could trust that the delayed reward would materialize) waited four times longer than children in the unreliable group. Were the kids in your test simply making a rational choice and assessing reliability? And wouldn’t that factor be outside the scope of the original Marshmallow Tests?

Mischel: This is another thing the media regularly misses. Before the marshmallow experiments, I researched trust in decision-making for adults and children. Trust is a tremendous issue. Therefore, in the Marshmallow Tests, the first thing we do is make sure the researcher is someone who is extremely familiar to the child and plays with them in the playroom before the test. It’s also important to realize, it’s not a matter of if somebody will come back with the two little marshmallows. They are all right there on the tray. It’s all out in the open, so there’s no trust issue about whether the marshmallows are real.