What is happiness? It's not being rich or feeling good all the time. It's a set of habits more than a destination. New research suggests that happiness is a combination of how satisfied you are with your life and how good you feel day-to-day. It turns out that about 40% of your happiness is controlled by your thoughts and actions, 10% by your circumstances, and the other half is genetic. It's hard to change your genetics and circumstances, but you can train your brain to be happier.