“Individuals with less social connection have disrupted sleep patterns, altered immune systems, more inflammation and higher levels of stress hormones. One recent study found that isolation increases the risk of heart disease by 29 percent and stroke by 32 percent.” And in another one of the ironies of the Internet age, “the percentage of American adults who say they’re lonely has doubled from 20 percent to 40 percent.” From NYT Upshot: How Social Isolation Is Killing Us.