June Gruber of Yale University in New Haven, Conn., Iris Mauss of the University of Denver and Maya Tamir of the Hebrew University of Jerusalem conducted a review of studies concerning the pursuit of happiness and found happiness has a dark side, too.
For example, one study tracked children from the 1920s to old age and found those rated as highly cheerful by their teachers died younger.
The review, published in Perspectives on Psychological Science, also found people feeling extreme amounts of happiness may not think as creatively as the less happy, and they also tend to take more risks.
The tools often suggested for increasing happiness -- such as taking time to think about what happened that day that made a person happy or grateful, or setting up situations that are likely to make you happy -- are good.
"But when you're doing it with the motivation or expectation that these things ought to make you happy, that can lead to disappointment and decreased happiness," Gruber says.
However, psychological scientists have discovered what appears to really increase happiness.
"The strongest predictor of happiness is not money, or external recognition through success or fame," Gruber says. "It's having meaningful social relationships."
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