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Dr. Nicholas Christakis is known for his research on the social factors that affect health, health care, and longevity. 

In his lecture "If You’re So Free, Why Do You Follow Others? The Sociology and Science Behind Social Networks," part of Floating University's Great Big Ideas course, Christakis explains why individual actions are inextricably linked to sociological pressures. Whether you’re absorbing altruism performed by someone you’ll never meet or deciding to jump off the Golden Gate Bridge, collective phenomena affect every aspect of your life.