Well, was it worth learning that about it?

Double-blind placebo controlled randomized skin color test

Oh my god THAT'S why his face is like that and THAT'S the joke. I really didn't get this comic.

Or hungrier kids (aka poorer kids) get the marshmallow first. Or those in greater need of serotonin (at least I think it's serotonin) you get from sugar, etc. There's a variety of issues here, but that's true of most "experiments" that aren't actually randomized controlled trial experiments.

Or it measured how rare it was for them to get candy. The most interesting thing about the experiment is honestly the many ways in which it was flawed.

Or they're just natural born addicts like myself and need that instant reward and think to hell with my future self. That's his problem. Present me just got a marshmallow.

I don't know what study you are referencing, but in ALL the behavior analytic literature on "self-control" that I know of, the experimenters provide the reinforcement as part of the study. Not only that, but there are usually repeated trials with the same individual to establish a baseline and some sort of experimental treatment to see if self-control-related behaviors can be shaped. If the research is done with individuals who are children or have Developmental Disabilities, they usually ask that whatever the reinforcers are be restricted for some amount of time prior to experimental sessions to minimize outside influence on the study. So, families are usually asked not to give that specific candy, or whatever, to the individual during the trial, but there will be a handful of opportunities to receive some.

Excerpts from Wikipedia:

A replication attempt with a sample from a more diverse population, over 10 times larger than the original study, showed only half the effect of the original study. The replication suggested that economic background, rather than willpower, explained the other half.

Work done in 2018 and 2024 found that the Marshmallow Test "does not reliably predict adult functioning".

It's great for a confirmation bias, but such a study is way too simplistic to really reach a conclusion. Oh, and:

The results seemed to indicate that not thinking about a reward enhances the ability to delay gratification, rather than focusing attention on the future reward.

later replications of the test showed that the difference between kids waiting or not, and successful or not was significantly related to their parents financial status, in other words, the broke kids ate the stuff that was in front of them, because they learned that promises are not always kept

the study didn't account that many kids assumed the guy was lying

You might want to try a different brand of sex tbh. It's gotta have serious issues to get beaten out by some fluffy sugar.

Tell me where

This is a cognitive task aiming to assess whether kids can trade a small reward now for a bigger one later (it tests inhibitory control and ability to project oneself in the future). This experiment was conducted by comparative psychologists and, if I recall well, they also compared the kid's performance to that of some primates to understand the evolution of the human mind.