Squeaky stairs and the Upside Down Marshmallow test

Friday, August 29, 2025

I learned by my teens that the sides of stairs don’t squeak. I needed to stay inaudible and invisible to my parents while they screamed at each other in the living room.

Even though it was past bedtime, I knew they could easily turn their venomous, never ending vitriol on me instead of each other, and I needed to hear them to get an early warning. That was why I was creeping down the stairs. And I needed to stay invisible while I got close enough to the plywood doors in their 1960s suburban chalet while I did it.

My parents had been screaming at each since I could remember. Well, almost. There were periods of tense silence, peaking with the glorious happiness of a few hours here and there where there was no tension at all. But ‘assume screaming’ was the safe money option.

There was always the danger, as my bare feet stepped softly down the stairs’ cheap nylon carpet, that the door would burst open and they’d catch me spying on them. Disappearing like Bilbo Baggins would have been ideal but I had no magical ring.

So my Plan B was to divert to the kitchen, pretending I was coming downstairs from the safety of my bedroom to get a snack. The dog had learned a similar trick in reverse — if a human spotted it heading upstairs, it had learned to abort quickly and steer into my father’s office at the bottom of the stairs.

It generally worked. In fact, over a couple of years, I used Plan B enough that I put on a lot of weight, making me even less likely to disappear even though I wanted to more and more.

I hit a downward spiral. I got fatter, I hated myself even more, became more anxious, needed to know what was going on even more, ate more chocolate biscuits, became larger, got more of a sugar hit, ate more chocolate biscuits, got fatter.

On the photos from my 18th birthday, I was puzzled by the why my shirt seemed to take a long way down to reach my jeans. Friends pointed out it had to go over my belly.

Somewhere in my head, I knew I was miserable, and rationally it seemed likely that there was more going on than my mother’s opinion of greed and laziness.

Turns out my intuition was right, because there’s a pretty convincing theory that, sugar addiction aside, trauma can play out by not being able to resist food.

It’s a spin on the Marshmallow Test [link]. You get a young — probably pre school age — child and put them in a room with a marshmallow on the table. Then you leave them, saying you’ll be back later and you’ll bring another marshmallow, which they can have if they’re a well behaved child and don’t eat the one in front of them while they’re alone.

With this paper from 1970 and this paper from 1972 to back it up.

Like anyone under well-designed torture, the subjects almost always break. Fortunately for university research ethics committees, the downside is they get a marshmallow instead of life changing injuries. Eating cupcake is not yet a life-changing injury. The only metric is how long it takes.

And that metric, for the sadists who designed this experiment, measures executive function, and specifically the element of executive function we call self control. The longer you hold back from wolfing the marshmallow, the better you’ll do as an adult.

It’s your adulting number, kind of.

I simplify grotesquely, but broadly speaking, it’s one of the best predictors of success in future life. When the experiment was originally carried out, it looked like self control was innate, or close enough. Maybe it came from intelligence, maybe imagination, but whatever, it was interpreted as a cause, not an effect. Besides, an effect of what, exactly?

For forty years.

Then researchers had another think about it, and upended the cupcake to consider if it might be the effect of something. Like, say the trauma of growing up with parents who saw you as the convenient one-stop destination for their own apocalyptic dysfunction.

How would that work?

Often one of markers of a traumatic environment is unpredictability. Abusers give, and abusers take away, and they do it randomly in order to create their effects (which you could trace back to B F Skinner and his rats, if you wanted, but nobody does because determinism is frowned upon these days).

More on Skinner and his rats here and here.

Plus a video.

Case in point. Once when I was at high school, I forgot I had band practice and got home from school an hour and a half late, bracing myself for my mother’s fury at not telling her. But she didn’t notice. A couple of days later, I got in ten minutes late and got a full on vitriol-bombardment, the kind that only the children of abusers understand.

With good-enough parenting, a child does a thing, and their your parent responds. You draw a conclusion - this was a bad thing, not to be repeated, or a good thing to be done as much as possible.

With the dysfunction outsourcing model of parenting, next time that situation comes up, you carefully avoid doing it — and you get screamed at for not doing it. Or, if it was apparently a good thing the first time, you’re careful to do it again. This time however, it’s a mortal sin and you are damned for all time.

The child can’t draw any inferences about how the world works, and since drawing inferences about the world is one of the main things children spend their time doing, it is most definitely A Thing.

The parent acts like this because to them, the child is just the outsourcing contractor for their own dysfunction. The dysfunction is too intense for the parent to think about anything else, such as the effect on their child.

It helps that people are more malleable when they don’t have a clue what’s going on. When the child is baffled and scared, it’s going to hide and let the parent get on with their dysfunction, which is what the parent wants. So for a parent on the Dark Triad as my mother probably was, it’s win-win.

Meanwhile, the child concludes that the future is entirely beyond prediction, let alone control, so logically, the most rational option becomes to grab what you can, when you can.

Like marshmallows.

Someone might take it off you, randomly. So eat it now. Eat all of them now.

It doesn’t take a genius to extend the principle: eat all chocolate, drink all the beer, pop all the drugs, shag all the strangers, spend all the pay cheque.

Your brain lives in a scarcity market where it’s logical to not wait. Executive function, schmexecutive function.

So back to little me sneaking past the living room door, feet on the non-squeaking sides of the stairs, stressed about being caught. My logical solution - ‘just getting a snack’ was fine in the moment: sugar, dopamine, quelling the cortisol and avoiding getting screamed at.

In the longer term, of course I got fat.

The question, as Marx pointed out, was to change it.

More of the same, it turns out, for me, until a few years ago, and alone and emotionally broken, and with the line from Les Miserables ‘… no one is coming to help you to die’ in my head, I decided I needed to do something different. Anything, pretty much.

So I started Couch to 5k, and I’ve kept it up since, and added a bunch of other sportsing to my life. Planned runs and other sportsing, planned meals, planned work stuff.

Weirdly for teenage me, I enjoy the sportsing and the eating healthily that goes with it. I’m terrible at sport and I’ve always liked fruit and veg and the healthy stuff. There are biochemicals going on with this of course, but maybe something else. It feels like I’ve flipped the cupcake. If unpredictability caused the lack of impulse control, then being predictable, routine, and generally boring (compared at least to the random emotional apocalypse of my childhood) makes impulse control easier. I know what’s coming. I have my weeks, days, hours planned. I’m no longer frozen on the stairs waiting for the living room door to fly open and the terrible onslaught to start.