Screenshot from "The Great Brain Experiment" app. Today

The key to happiness could be low expectations — at least, that is the lesson from a new equation that researchers used to predict how happy someone would be in the future.

In a new study, researchers found that it didn't matter so much whether things were going well. It mattered whether they were going better than expected.

"It is often said that you will be happier if your expectations are lower,” Dr. Robb Rutledge, the senior research associate at University College London (UCL) who led the study, said in a statement. “We find that there is some truth to this: Lower expectations make it more likely that an outcome will exceed those expectations and have a positive impact on happiness.”

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Not that you should walk around gloomy all of the time. Having expectations at all — say, for a lunch date with a friend — can lift your spirits “as soon as you make the plan,” Rutledge said.

But anticipating the greatest meal of your life could result in feeling pretty disappointed. No, this study was not meant to ruin your lunch plans. Instead, researchers wanted to figure out a way to give doctors a subjective, quantitative way to measure mood disorders.

The study involved two parts. First, 26 subjects made decisions that led to financial wins or losses, all while being monitored by an MRI machine. Later, 18,420 people played a game called “The Great Brain Experiment,” which replicated the experiment with points instead of money.

Ultimately, the researchers found that it was not the amount of total money or points won that mattered — it was how winning or losing stacked up to expectations formed during past experiences.



This is the happiness equation. Today

They even came up with a mathematical equation that could accurately predict how happy someone would be during the money experiment and while playing the smartphone game. Eventually, researchers said, it might be able to help doctors predict how people with mood disorders might react to the small wins and losses of everyday life.

The study was published in the Proceedings of the National Academy of Sciences.

Keith Wagstaff writes about technology for NBC News. He previously covered technology for TIME's Techland and wrote about politics as a staff writer at TheWeek.com. You can follow him on Twitter at @kwagstaff and reach him by email at: Keith.Wagstaff@nbcuni.com







