What is the secret to happiness? The age-old question has beguiled poets and philosophers alike. Now, scientists are forgoing melancholic approach for a more methodical approach, unveiling a new equation for predicting happiness in a Nature Communications paper. The study authors built on an earlier version of the equation they had published in 2014, which factored in the influence of expectations. Their updated equation also accounts for inequality, reflecting that happiness depends on what befalls no only us, but also those around us. In other words, our happiness drops when others receive more or less than we do.
The equation can also predict generosity based on how an unequal outcome affects someone’s happiness. Archy de Berker and Robb Rutledge, both of University College London, led the study amid staggering inequality around the world. Research has also shown that countries with high levels of equality like Iceland and the Netherlands rank highly in well-being. That may be because “individuals themselves might be inequality averse,” de Berker says.
To understand how inequality affects happiness, de Berker’s team recruited 47 adults to participate in a so-called dictator game. The researchers gave the participants a sum of money and asked how much they wanted to split with a partner, with the disclaimer that the partner would not know the donation amount. They then played several rounds of a gambling computer game, also with a partner. A screen displayed the outcome of their partner’s gamble in addition to their own. Every few rounds, the researchers asked participants to rate their happiness by plotting it on a horizontal line, with the left side marked “very unhappy” and the right marked “very happy.” On average, participants’ happiness decreased when their partner experienced a different outcome from their own, regardless of whether they themselves had won or lost. They felt happiest when they and their partner both won — even happier than when they won, and their partner lost. In fact, they felt happier when both they and their partner lost versus when they lost and their partner won. For each participant, the researchers compared happiness levels when the participant and his or her partner experienced unequal outcomes. Participants who felt happier on average when they lost and their partner won — those for whom guilt played a bigger role in their happiness — were more generous in the dictator game. In fact, they gave away three times more money than participants who felt happier when they won and their partner lost — those for whom envy played a bigger role in their happiness. The researchers then added terms to their earlier equation to account for the influences of envy and guilt, resulting in a model that predicts happiness and generosity.
To be sure, the equation represents “happiness in this particular task, not some model of general happiness,” says Elizabeth Tricomi of Rutgers University. In the real world, “other things matter besides whether someone is making more or less than you.” Tricomi also wonders how accurately the equation predicts happiness and generosity in the long term — for example, even after spotting a dent in your car the next day. But overall, “it was a nice study,” she says, and we can’t expect a comprehensive model of happiness based on a single study. De Berker acknowledges that his team’s equation “is a reasonable approximation to the real world, but obviously it is quite different.” For instance, how you feel about a co-worker earning more than you might also depend on how hard each of you works, which a game of chance can’t replicate. Besides shedding light on how to lead happier lives, “we can use these same kinds of equations to understand what happens when happiness goes wrong”, as well as design and predict the helpfulness of clinical interventions, de Berker says. He and his team are identifying the brain chemicals involved in activities like those in the study, and how they affect happiness and generosity. For now, people very much care about what other people have in relation to themselves.