The Easiest Way to Control How Much We Eat

Two Large Popcorn Containers

This post is part of an ongoing series of mini-posts entitled Daily Learning, wherein I attempt to convey some interesting factoid that I learned that day and my very brief thoughts on it.

What I Learned

Container size matters. A lot.

Researchers at Cornell University ran a study on 158 moviegoers examining their popcorn-eating habits. The goal was to study the effect of the popcorn containers’ size on the amount of popcorn consumed. Each participant received a giant tub of popcorn—more than any normal person could consume in the span of a 2-hour movie. But for half of them, the effectively-infinite supply of popcorn was twice the size. To rule out the effect of taste, for half of the study they used 14-day-old, stale popcorn; people ate the popcorn because it was there, not because it was delicious.

After the movie, participants were asked “Do you think the size of the popcorn bucket had any effect on how much you ate?” to which there was an almost universal response of “No, of course not.”

The numbers told a different story.

The moviegoers who had been given a double-sized infinite-supply of fresh popcorn ended up eating 45.3% more than their half-sized counterparts. With the stale popcorn this effected was diminished to a still amazing 33.6%.

Where I Learned It

The Invisibilia podcast episode “Frame of Reference.”

What I Thought

This principle can be used for the manipulation of both others and of our own selves. I’ll leave the former to your imagination, but an example of the latter that comes up often (in my life at least) is the consumption of ice cream.

The age-old dilemma: The hour is late. Bed time approacheth. But first—a bit of that sweet, creamy good stuff for a proper send-off to dreamland. But how to eat it? Should I just take the whole container out of the freezer and go to town with a spoon? Or maybe I should do that whole “civilized” thing and scoop some into a cup first?

The results of this study would definitely point towards the couth option as being also the smarter one. Especially if you typically buy the larger tubs rather than the small pints. Even if you know that you don’t plan on eating a whole tub (infinite supply in either case), you will still end up eating more than if you had restricted yourself at the beginning through spooning a set amount into a separate cup.

Conversely, it’s best to eat veggies in large bowls.

What it Relates To

1. Anchoring.

The psychological principle that describes how our brains latch onto the first quantity of something that we see and use it as a set point. One of the most common instances of this is in shopping—if a store initially labels an item as $149, then subsequently marks it down to $69.99, your brain will tell you that you’re getting a great deal. Even if they never actually sold it at the non-reduced price. This works even when what they are doing is completely obvious; the number of times I’ve heard a friend brag about getting three “$800” suits from Men’s Warehouse for “Only $750 in total!” boggles my mind. Or, more accurately, the fact that they seem to believe that each of said suits is actually comparable in quality to a suit that would be SOLD for $800 by another brand is what is doing the boggling.

2. Degrees of infinity.

For those of you nerdy folk out there who care about cool mathematical nuances, this article brought to mind the concept of how not all infinities are created equal. For example, the number of decimal numbers in between 0 and 1 is infinitely times more numerous than the total number of possible integers. These are referred to as degrees of infinity, represented by Aleph-0 and Aleph-1. If you can’t figure out how this makes any sense, see here for a nice explanation.