Be happy - it seems to be good for your heart.
Scientists have long known that Type A personalities and people who are chronically angry, anxious or depressed have a higher risk of heart attacks.
Now a Harvard review of the flip side of that psychology concludes that being upbeat and optimistic just may help protect against heart disease.
Rather than focusing only on how to lessen heart risks, "it might also be useful to focus on how we might bolster the positive side of things," said lead researcher Julia Boehm of the Harvard School of Public Health.
Boehm reviewed dozens of studies examining a positive outlook - as determined by various psychological measurements - on heart health. Optimism in particular seems key, as a number of studies found the most optimistic people had half the risk of a first heart attack when compared to the least optimistic, Boehm said.
Previous work shows the stress associated with negative psychological traits can lead to damage of arteries and the heart itself.