What makes us happy is always changing with our expectations.

Credit: Wikimedia Commons

This was summed in a 2014 equation developed by a team at University College London. Now, the same group has updated the equation to account for other people’s happiness. Based on the results of two experiments, the new variable suggests our overall “happiness score” can be significantly brought down or up depending on how happy the people around us are. Not surprisingly, inequality is a major negative factor.

For this study, 47 healthy volunteers who did not know each other were enlisted . Each participant was paired up with a stranger and asked how they would like to split an arbitrary amount of money with the other person. Keep it all, makes it 50/50, give it away, it was all up to each volunteer.

In the next task, the volunteers had to gamble in games where they could either win or lose money, but were told how other people faired at the same games. Sometimes, these other players earned more or less, and throughout this experiment, the study’s participants were asked how happy they felt at regular intervals.

On average, when someone won a gamble they were happier when their partner also won the gamble, compared to when they lost. This effect the researchers attribute to guilt. When the gamble didn’t pay off, players felt happier when their partners also lost, compared to when they won. This was attributed to envy.

“Our equation can predict exactly how happy people will be based not only on what happens to them but also what happens to the people around them,” explains one of the study‘s co-lead authors, Dr Robb Rutledge (UCL Institute of Neurology and Max Planck UCL Centre for Computational Psychiatry and Ageing Research).

“On average we are less happy if others get more or less than us, but this varies a lot from person to person. Interestingly, the equation allows us to predict how generous an individual will be in a separate scenario when they are asked how they would like to split a small amount of money with another person. Based on exactly how inequality affects their happiness, we can predict which individuals will be altruistic.”

This is the so-called “happiness equation”. As you can well see, happiness can be very complicated and depends on quite a few inner and external factors, ranging from material status, to how other people fair in their own lives. Credit: Nature Communications

The results tell us whether people felt happier, hence more generous. This did not depend on who the partner was or if they liked other people gambling alongside. It made absolutely no difference who that other person was or what they meant to the player — only their scores. For instance, people who won more felt their happiness threatened by guilt and chose to give away, on average, 30 percent of their money. On the other hand, those who earned less than others gave only 10 percent.

“Our results suggest that generosity towards strangers relates to how our happiness is affected by the inequalities we experience in our daily life,” says Archy de Berker (UCL Institute of Neurology), co-lead author of the study,

“The people who gave away half of their money when they had the opportunity showed no envy when they experienced inequality in a different task but showed a lot of guilt. By contrast, those who kept all the money for themselves displayed no signs of guilt in the other task but displayed a lot of envy. This is the first time that people’s generosity has been directly linked to how inequality affects their happiness. Economists have had difficulty explaining why some people are more generous than others, and our experiments offers an explanation. The task may prove to be a useful way of measuring empathy, which could offer insight into social disorders such as borderline personality disorder. Such methods could help us better understand certain aspects of social disorders, such as indifference to the suffering of others.”