We long have been given tips on how to live a long life that includes exercise, diet and other healthy practices. Then, of course, there are genetic factors. David Hamilton in a recent column in The Huffington Post tells of a surprising new ingredient to a long and healthy life. The secret: friendship. He tells of a 2010 study at Brigham Young University involving 308,849 people. People with a strong social network had a 50 percent increase in the likelihood of survival over a 7.5 years period. Not only do people live longer and healthier, they live happier.