Set Point Theory: Does Happiness come from Genetics or Environment?
Set Point Theory
Is our chronic Happiness based on nature or nurture? In 1978 Phillip Brickman followed 22 lottery winners, a control group, and 29 paralyzed accident victims. They found that the recent accident victims reported gaining more Happiness from everyday pleasures than the lottery winners. Overall, Lottery winners were ahead in present Happiness but not in day-to-day Happiness from the paralyzed group. Why? The answer lies in the contrast effect. Winning a lottery makes you look for pleasures in big things and not in small matters. Due to this buzz-seeking, everyday mundane things do not give as much pleasure. The habituation effect tells you that paralyzed victims got habituated to their situation after a couple of years. Dr. Sonja Lyubomirsky proposed the set point theory. 
Nothing gives us 100% happiness. If Happiness is a pie, it has three main divisions.
1. Set Point theory:  proposes that no matter what happens, usually after a year or two, your genetic predisposition will lead you to settle down at a specific set point predetermined by your own genetic makeup. It applies to good and bad both. Getting married, getting a dream job or home, winning the lottery, or at other end, losing a loved one, break ups, or business loss.  Give and take two years, and you will revert to your set point of Happiness. Ten years of follow-up Twin studies have shown an 80% chance that monozygotic twins will remain at the same happiness level at the study’s end. Not so much for dizygotic twins. 
2. Outside Circumstances: We have this idea that if we’re not happy now, then we will become happy when x, y, and z happens: When I get married, I’ll be happy; when I strike it rich, I’ll be happy when I move to that city, I’ve always wanted to live in. The problem is that those events do make us happy—but they don’t make us as happy as we hope or for as long as we think they will. Watch the video here and the 20/20 piece on this here.  
3. Intentional Activities: The crux of the set point theory argues that your chronic Happiness can be altered (albeit only so much) by intentional activities. Healthy and happy people do things like exercise, work toward personal goals, devoting to a meaningful purpose, or cognitive restructuring to constantly stay ahead of setbacks. Here is a quick summary of 12 activities that can increase your life satisfaction and happiness. Soon, we will talk about how intentional activities can lead to Happiness
Set Point Theory in two minutes.