Because Type A personalities are defined by competitiveness, a drive to succeed, and a sense of urgency, they are prone to take risks and act without thinking, neither of which is likely to improve health. Non-Type A's can be impulsive, too. Such people are often not as well-grounded as others, says Robin Belamaric, a clinical psychologist in Bethesda, Md.: "They'll look at an opportunity that comes along and say, 'Hmm, that sounds like fun,' whereas another, more thoughtful person, will say, 'I'm going to pass, because I'm not sure it's the best idea.' "