The equation looks at expectations, rewards and past outcomes
“We can look at past decisions and outcomes and predict exactly how happy you will say you are at any point in time,” said lead author Dr Robb Rutledge from University College London.
“The brain is trying to figure out what you should be doing in the world to get rewards, so all the decisions, expectations and the outcomes are information it’s using to make sure you make good decisions in the future. All of the recent expectations and rewards combine to determine your current state of happiness,” he told BBC News.
To build the mathematical model, the team analysed the results of 26 people doing a task in which, over repeated trials, they chose between definite and risky monetary rewards. Every few trials they were asked to report their level of happiness.
Participants’ brains were also scanned using fMRI (functional magnetic resonance imaging).
Activity in two areas of the brain correlated positively with happiness scores; these were the ventral striatum – a main source of dopamine neurons – and the insula, an area of the brain known to be important for several emotions including happiness.
The striatum was associated with changes in happiness and the insula with overall levels of happiness.
The equation was then applied to over 18,000 people who played a smartphone risk-reward game in The Great Brain Experiment app, which was recently shown to be a reliable way of studying cognitive behaviour.
The happiness equation | Nick Powdthavee | TEDxGhent