Happiness isn't being cheerful all the time

We're less likely to try new things as we grow older. C. Robert Cloninger, a professor of psychiatry, genetics, and psychology at the Washington University School of Medicine, found that between the ages of 20 and 60, novelty seeking drops off at a rate of about 10 percent per decade, which can make staying receptive to newness a challenge. "As we age, we need to try not to let ourselves get in a rut, but to continually challenge ourselves with new ideas," he says.