Friendship has a huge impact on overall health, according to several studies that emphasize the importance of social ties. In one Australian study, older people with a large circle of friends were 22 per cent less likely to die over a 10-year period than those with fewer friends. And in 2006, a study of almost 3,000 nurses with breast cancer found those without close friends were four times as likely to die from it as women with 10 friends or more. The proximity and amount of contact with these friends wasn’t associated with survival—just having them was protective. In another six-year study of 736 Swedish men, only smoking had as large an impact as social support on the risk of heart attack and fatal coronary disease. People with friends seem to have better access to health services; but it also has a psychological effect—for example, those with strong social bonds are less likely to come down with colds, maybe because of their lower stress levels. In a 2008 study from the University of Virginia, 34 students were taken to a steep hill and instructed to wear a weighted backpack, then asked to estimate the steepness of the hill. Some stood next to friends, and others were alone. Those with friends gave lower estimates of the steepness of the hill, and the longer they’d known each other, the less steep they thought it was. “People with stronger friendship networks feel like there is someone they can turn to,” Karen A. Roberto, director of the center for gerontology at Virginia Tech, told the New York Times. “Friendship is an undervalued resource. The consistent message of these studies is that friends make your life better.”