Study: Key to happiness is listen to others - Harvard University Want to know what will make you happy? Then ask a total stranger — or so says a new study from Harvard University, which shows that another person's experience is often more informative than your own best guess. People do not realize what a powerful source of information another person's experience can be, says Gilbert, because they mistakenly believe that everyone is remarkably different from everyone else. But the fact is that an alien who knew all the likes and dislikes of a single human being would know a great deal about the species. People believe that the best way to predict how happy they will be in the future is to know what their future holds, but what they should really want to know is how happy those who've been to the future actually turned out to be.