What is an instance of happiness?
That's a squishy question philosophers have discussed for millennia. According to Sparknotes, Aristotle said happiness is an end to itself. The poet Kahlil Galbraith wrote that happiness "is your sorrow unmasked," whatever that means.
Rhetoric aside, researchers at the University College London say happiness (or at least a discrete moment of it) is represented by the formula above, recently published in the Proceedings of the National Academy of Sciences. The gist of that formula is this: Happiness spikes when we win and our expectations are low—but that happiness gradually fades over time.
Image: Proceedings of the National Academy of Sciences
