Pessimists 1, optimists 0

If you’re an exceedingly sunny person, tone it down a bit. “People tend to think of cheerfulness as good, but we found exactly the opposite,” Martin says. “Cheerful kids lived shorter lives. That was a big shocker.”

Overly optimistic people tend not to be as careful as those who have a more serious take on life. “If you’re one of those people who expects things will always turn out great, you may benefit from listening to the perspectives of others,” Martin says. “Awareness is a key component. And being a little more prepared and a little more risk-averse.”