Your personality may be the key to a very long life. A study examined the personality traits of 246 children of people who lived to be at least 100. (Offspring of centenarians were chosen because they tend to be long-lived and don't die as often as the very aged before research can be completed.) The study showed that those who live the longest are more outgoing, more active and less neurotic than other people. Long-living women are also more likely to be empathetic and cooperative than women with normal life spans.