A decades-long study at Harvard University came to the conclusion that the ability to be intimate with another person was one of the strongest predictors of health and happiness. Those people who were commitment-phobic or intimacy-phobic were among the unhappiest people. (Of course these findings only apply to “rational” love and not unrequited, abusive, obsessive, or harmful love.) So, choose a partner whom you can love and respect and who feels the same way about you. Show affection: kiss, cuddle, and compliment your partner often. Share your troubles and your triumphs, your fears and your dreams. Evidence shows that a good, solid relationship will not only make you happier, it may even help you live longer.