You may have also heard that you are the average of your five closest friends. Sociologists have taken this a step further in their studies. It is not just how you are influenced but your five closest friends, but by who influences friends of friends. They tracked it through obesity and drug use. Obese friends make you 45% more likely to gain weight over the next two to four years. If a friend of a friend becomes obese, your likelihood of gaining weight increases by 20%. Drug use had similar results at 61%, 29% and 11%. The same is true of happiness. If a friend of a friend of a friend is happy, you are 6% more likely to be happy yourself or experience a 6% increase in happiness. While 6% may not sound like much, if you all got a $10,000 raise it would only trigger a 2% increase in your happiness.