You know the marshmallow experiment?
So there’s this experiment where researchers take a bunch of preschoolers and give them a marshmallow and they say, “ok, you can eat this now, or you can wait thirty minutes and then we’ll give you two marshmallows.”
And they leave them alone with hidden cameras and watch the struggle of willpower and it’s supposed to say something about delayed gratification.
And this thing gets used to explain why some people are better with money than others, or make various other better life choices. The Aesop here is if you can delay your satisfaction, you’ll get ahead.
But here’s a proposed version of that experiment that’s more realistic.
Give the kid the marshmallow and explain it all as above. Then come back 30 minutes later and say, “Sorry, actually we ran out of marshmallows, so even though you didn’t eat yours, you’re not getting a second one. Other kids got two, but you don’t. Also, every kid with fewer than two marshmallows has to give back their original marshmallow. Sorry we didn’t tell you that earlier now hand it over.”
Then call them back for a repeat experiment where you give them the same offer. See how many kids scarf that marshmallow down in two seconds flat because like hell they’ll trust you again.
If it’s the experiment I’m thinking of they did run the experiment again, and this time did take into account something they didn’t before: the socio-economic level of the children involved and if there had been broken promises made before to them. Children from lower socio-economic circumstances who had been let down in the past were far more likely to eat the marshmallow the first time around. The experimenters then showed the kids they had the two marshmallows to give them and let them out.
Then comes the fun part: they ran the experiment again.
This time, those kids who ate the marshmallow before waited. Without any further prompting than keeping their word, the scientists destroyed the notion that children in poverty are more prone to poor impulse control or are more likely to scarf down sugar than rich kids.
Oh now that is interesting! I’d never heard that follow-up before.
When I first learned about this case study in college, something about it felt incomplete, but I could never really put my finger on it. It seemed overly simplistic, but I couldn’t see the missing piece because in was in one of my cognitive blind spots.
Knowing about this follow up is incredibly valuable and insightful!
And this is why it’s vital for human beings to check our assumptions and always be on the lookout for cognitive blind spots. Because even one missing variable can mean the difference between transformative insight and generations of deeply embedded misconceptions.
This is also why it’s important for the scientific community to actively seek out scientists with diverse backgrounds and perspectives. It’s not about arbitrary “diversity quotas,” it’s about pursuing a diversity of insight.
I saw a different follow up study illustrating this same point. They set up three “wait to get more” situations, except that the first two were set up so the kid couldn’t actually open the container the things were in (stickers & broken crayons – they were promised cooler stickers and unbroken crayons).
Half of the kids were randomly assigned to get the promised better stuff when the adult returns, while the other half the adult returned apologetically without the promised stuff and just helped them open the container.
When they came to the third situation, which was the marshmallow test, the kids who’d just had the experimenter keep two promises were more likely to wait than the kids who’d just had the experimenter break two promises.