Back in 2014, a team of researchers came up with an equation to predict happiness and now, they have updated it to take other people's fortunes into account.
Developed by UCL researchers, the new equation shows how our happiness depends not only on what happens to us but also how this compares to other people.
The changes found that inequality reduced happiness on average. This was true whether people were doing better or worse than another person they had just met. The subjects played gambles to try to win money and saw whether another person won or lost the same gambles.
On average, when someone won a gamble they were happier when their partner also won the same gamble compared to when their partner lost. This difference could be attributed to guilt. Similarly, when people lost a gamble they were happier when their partner also lost compared to when their partner won, a difference that could be attributed to envy.
Co-lead author Dr Robb Rutledge explained, "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."
For the study, 47 volunteers who did not know each other completed several tasks in small groups.
"Our results suggest that generosity towards strangers relates to how our happiness is affected by the inequalities we experience in our daily life," said co-lead author Archy de Berker, adding "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."
Berker noted that economists have had difficulty explaining why some people are more generous than others and the experiments offer 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 researchers better understand certain aspects of social disorders, such as indifference to the suffering of other
The study is published in Nature Communications.