Huffington Post:

Think of it this way: We are all born with certain genetic strengths and weaknesses. Perhaps you have a family history of diabetes. There’s nothing you can do to change your genetics, but there are many things you can do to lower your risks: watch your diet, exercise, avoid smoking, work with a physician to make sure you’re getting the proper screenings, and so forth.So it is with happiness. You’re wired a certain way, certainly, but when it comes to enjoying life, genetics are not destiny, and there is much that you can do to increase your own experience of happiness.