Researchers have developed an equation that can accurately predict how happy an individual is at any given point in time. It seems our happiness is not based on how well things are going, but how much better they are than our expectations. Although the equation is insightful for all, it’s what it may mean for the world of mental health that really has us buzzing.

Researchers from University City London in the UK analyzed the relationship between happiness and reward, and took a look at the neural process that causes feelings of elation. In their study, 26 participants completed a decision-making task that could either end in willing or losing money. While completing the task, participants were repeatedly asked “how happy are you right now,” as a functional MRI measured their brain activity. From these results, the happiness equation was born, a rather complicated mathematical equation that can predict just how happy a person is.

To test their equation on a larger scale, researchers developed the smartphone app, The Great Brain Experiment. Over 18,000 participants worldwide played The Great Brain Experiment, and the happiness equation proved successful in correctly predicting the gamers' happiness levels.

math equation
The Happiness Equation. Photo courtesy of Professor Robb Rutledge/University College London. Photo courtesy of Prof. Robb Rutledge/University College London

How Our Expectations Influence Happiness

Dr. Robb Rutledge, lead researcher on the study, told Medical Daily in an email just how important being able to measure happiness is. “If we want to understand happiness, one thing we need to do is measure it and find out exactly what determines it,” he explained. The study’s results revealed that expectations are just as an important factor in moment-to-moment happiness as recent rewards.

This means that while it still remains true that happiness can be achieved by having lower expectations. Ultimately, it was found that participants were happiest when they did better than expected during a risk-reward task, Time reported. This would make happiness largely dependent on the size of the gap between what we achieve and what we expect. As Professor Andrew Oswald, a behavioral economist at the University of Warwick told the BBC, “If you want to know how happy I am, don't ask me my salary. Ask me how my salary compares to other professors or to my own salary in the past.”

Still, having positive expectations about an event can also increase momentary happiness. For example, Rutledge explained that “If you have plans to meet a friend at your favourite restaurant, those positive expectations may increase your happiness as soon as you make the plan.”

Mental Health

So what’s going on in our brains to make us happy? On a subconscious level, our brains are constantly seeking rewards and satisfaction. When we make a decision, the brain is trying to figure out the best choice to lead it to a reward. All decisions, expectations, and outcomes are stored and then used to help us again make good choices in the future. “All of the recent expectations and rewards combine to determine your current state of happiness," Rutledge told the BBC.

Rutledge told Medical Daily that he believes that his study may be helpful in developing better treatments for individuals suffering from mental health conditions. “We're now testing people that suffer from depression and trying to see whether our equation can predict their happiness, and seeing if we can find something different about how they make decisions, or how they respond to rewards,” he wrote. Being able to predict what will make an individual happy or not could help researchers better understand what triggers certain mood disorders, and “we may be able to help those people more,” Rutledge said.

Source: Rutledge RB, Skandali N, Dayan P, Dolan RJ. A computational and neural model of momentary subjective well-being. PNAS. 2013.