In the un-put-downable book Switch: How to Change Things When Change is Hard, the authors describe a famous popcorn study. Moviegoers were given a soda and a free bucket of popcorn on their way to see a 1:05 matinee of Mel Gibson’s Payback in 2000. They were handed either a medium size bucket or a large bucket—as the authors describe, looked like “the sort of tub that had once been an above-ground swimming pool.”

Unbeknownst to the moviegoers, the popcorn was stale. It was intentionally nasty— it had been popped five days earlier and was so stale that it “squeaked when you ate it.”

The researchers were exploring whether people with the bigger buckets would eat more popcorn. To precisely measure how much people ate, they weighed the buckets before and after the movie. The results shocked them: those with the large buckets ate 53 percent more popcorn than those with the medium size buckets. They quote the author of the study, highlighting how across the board, a bigger bucket leads to more eating:

We’ve run other popcorn studies, and the results are always the same, however we tweaked the details. It didn’t matter if our moviegoers were in Pennsylvania, Illinois, or Iowa, and it didn’t matter what kind of movie was showing; all of our popcorn studies led to the same conclusion. People eat more when you give them a bigger container. Period.

This research has implications for public health. As this study shows, people eat out of habit regardless of whether the popcorn tastes like Styrofoam peanuts. So rather than trying to educate them about switching habits or encouraging them to adopt better-snacking behaviors, there is a simple solution. Give them smaller buckets.

As the authors conclude:

What looks like a people problem is often a situation problem.

Bottom line:  Keep this in mind next time you are trying to make a small or big change.

“What do you want to be when you grow up?” is a question we ask children all the time. It asks them to think beyond the here and now and to imagine themselves in the future. However, imagining oneself 20 years from now is not something we as adults routinely do. According to research, perhaps it should be. Catching a glimpse of your future self may be an effective motivation strategy to changing behavior in positive ways.

Participants in a study were shown digitally altered images of themselves made to look their grandparents age—about 70 years old – while a control group was shown a current image of themselves. Each group was then presented with questions about finances and retirement. Those who had been presented with the image of their older self—wrinkles, jowls and receding hairlines and all—were willing to put twice as much money into long term savings accounts than those presented with a current image of themselves.

In a related study, participants were asked to connect to their future self in a different way: by taking five minutes to write a short letter to the person they will be 20 years from now. Instructions included: “Write about the person you are now, which topics are important and dear to you, and how you see your life.”  A control group was given the same instructions except the recipient would be them only three months down the road. Each group was then presented with various hypothetical scenarios designed to assess ethical decision-making. For example, would you buy a computer that “fell off a truck?” The group that had written letters to their distant future selves were less likely to engage in deceitful or delinquent behavior.

These studies have practical implications for the real world. By connecting people to the person they will be at age 70 in a concrete way, it is more likely they will make better decisions in the here and now. Some suggest putting visual renderings of a person’s aged face on credit cards and at cash machines to encourage smart spending. Binge eating, substance abuse and other impulse behaviors could also be affected by considering one’s future self. Even crime researchers recognize it is a tool to encourage first offenders to think about consequences of their actions and to deter crime in general.

Behavior today impacts the person you will become in the future. You Only Live Once, or YOLO, may be the current cultural refrain, but long-term thinking is essential for the well-being of individuals and society.

Next time you are about to do something impulsive stop and ask, “What would your future self think?” Another option is to download AgingBooth, an app that digitally ages photos of users. The photos are simultaneously hilarious and terrifying. I promise you one thing: seeing the wrinkles that await you will make you reconsider the rare social cigarette.