Americans are spending more and more time alone, and more than a third reported experiencing “serious loneliness" in 2021. The director of the Harvard Study of Adult Development -- the longest study of human life ever conducted -- concluded in a new book that close personal relationships are the "one crucial factor [that] stands out for the consistency and power of its ties to physical health, mental health and longevity." A lack of those relationships can actually have an impact on political behavior and interest in extreme ideologies. Galen Druke speaks with the director of the Harvard study, Robert Waldinger, about the lessons his findings have for politics in America. Learn more about your ad choices. Visit megaphone.fm/adchoices