Here’s The Equation For Happiness

If you thought human emotions were unpredictable, nuanced, and layered things, think again. In a recent study published in the Proceedings of the National Academy of Sciences, researchers at University College London shared the equation for happiness. The formula basically states that, for everything that happens to you (t), happiness is a factor of how important that event is (w), when it occurred (y), and whether or not the reward for the event exceeded your expectations (RPE). In the words of the lead author of the study, Robb Rutledge, PhD, “Happiness depends not on how well things are going, but on whether things are going better or worse than expected.” Check out the full equation here.

In order to quantify happiness, the researchers had 26 participants complete decision-making tasks in which their choices either resulted in monetary gains or losses. The researchers used functional MRI imaging to measure subjects’ brain activity throughout the experiment, repeatedly asking participants “How happy are you now?” Based on the gathered data, they created the aforementioned model for self-reported, moment-to-moment happiness. Since 26 is a pretty miniscule sample size, the researchers then put their formula to the test via none other than a smartphone app: a points-only gambling game deemed The Great Brain Experiment.

Based on the over 200,000 happiness ratings of the 18,420 players who tuned in, Rutledge, who is senior research associate at the Max Planck UCL Centre for Computational Psychiatry and Aging, found that his formula for happiness did, in fact, hold outside the lab. The players made the same types of decisions and subsequently reported the same levels of happiness as the original 26 participants. "Their happiness depended on their previous decisions and the outcomes...in exactly the same way as [in] the lab," Rutledge stated.

Of course, for those who suffer from mood disorders or have endured serious emotional trauma, this formula goes out the window. But, for the gamers, at least, the old theory that keeping your expectations low regarding an unknown outcome means you'll never be disappointed rang true: People who expected less reported higher levels of contentment.

However, before you resolve to adopt an Eeyore-esque outlook on life, consider this: The experimenters also found that their expectations for positive events actually increased levels of happiness before the event occurred. So, when you book that island getaway or make dinner reservations at your favorite restaurant, enjoy that anticipatory happiness buzz — but don’t get over-excited. "In general," Dr. Rutledge concludes, "If you have accurate expectations, you’ll make good decisions."