While it seems that everyone is searching for the answer to the age-old question, “What is the secret of happiness?” A better question could be, “Is it possible to be happier?” Some people simply tend to be happier and more optimistic than others. But that doesn’t mean you can’t improve your happiness if it doesn’t come naturally. In fact, research shows that 40 percent of people’s happiness comes from the choices they make.

So, what’s the right choice for happiness? You might find inspiration from participants in the Harvard Study of Adult Development, one of the longest-running happiness studies. The project followed 724 adolescents since 1938 . (There were about 60 men left, now in their 90s.) The group consisted of men from various economic and social backgrounds, from the poorest neighborhoods of Boston to Harvard students. Over the years, researchers collected various health information and every two years, they asked members about their lives and their mental and emotional health. They even interviewed family members. They found that specific traits and behaviors were associated with improved well-being in the group.

Project directors said that as people age, they tend to focus more on things that matter to them and worry less about minor things than they did when they were younger. Other research supports this line of thinking and reveals that older individuals are better at letting go of past failures. “They tend to realize how short life is, and there’s a greater likelihood they’ll pay more attention to what currently makes them happy,” says Dr. Waldinger. And you can do the same. What activities make you happy and which ones prevent you from doing them? Remember your childhood. What did you enjoy when you were young? Singing? Playing games? Do you have a special hobby? “As you age, you have more opportunities to re-engage in happiness-related activities.” So start collecting coins, join a choir, or play poker or bridge.