In the age-old dispute between Nature v. Nurture, nurture just won a round. A new study shows that our natural tendency to feel depressed or anxious may have more to do with life experiences than genetics.What does that mean for you? If you feel like you’re destined to be a half-glass-empty gal, fear not. Science now shows you can craft your life in your favor.Whether a friend’s passing gets you down or a wedding has you riding high, you eventually drift back to what psychologists call your emotional “set point,” meaning your usual tendency to experience anxiety and depression—your baseline.But what sets the set point?“The overwhelming view within psychiatry and psychology is that [your set point] is due to genetic factors,” Kenneth Kendler, M.D., a psychiatrist at Virginia Commonwealth University School of Medicine, said in a statement. Kendler challenges that view. He believes that experiences may have a powerful effect on mood.So he put his theory to the test.Kendler and colleagues pooled data from nine studies that included more than 12,000 twins from three continents, ranging in age from 11 to 67. Each reported their symptoms of depression and anxiety several times over a period of five to six years. (Twins have identical genetics but different life experiences, so they’re the gold standard for testing the effects of nature versus nurture.)A clear pattern emerged: The set points of 10-year-old twins were similar, but they slowly drifted apart until they were quite different by age 60. In other words, genes have some influence on mood, but it’s life that really shapes how you feel.QUIZ: You have the power to change your life. Start now! Take the Happiness Quiz.“Environmental experiences have a memory and stay with us,” says Kendler. How you react to those experiences determines how well you cope.“Different people will be affected by the same experience in different ways,” adds Art Markman, Ph.D., YouBeauty Psychology Advisor. “The issue is learning to recognize your patterns of reaction.”Kendler offers this advice: “If you want to be happy in old age, live a good life.”While that might sound easier said than done, give yourself a vote of confidence. Whether you choose to weather life’s storms with mindfulness, journaling, therapy or friendship, you have the power to shape how you feel.DISCUSS: Join our YouTalk discussion about how you handle life’s ups and downs.