John T. Cacioppo—the psychologist known as ‘Dr. Loneliness’—dies

John T. Cacioppo, whose research into human bonds and connections expanded the horizons of psychology, generating an entirely new discipline—social neuroscience— key insights into loneliness, died March 5 at his home in Chicago. He was 66.

The cause was not immediately known, said his wife, Stephanie Cacioppo, a fellow University of Chicago scholar.

An unlikely academic who became the first member of his family to graduate from college, Dr. Cacioppo was president of a dizzying array of psychological societies, the founder of several research journals and a scholastic pillar of the University of Chicago.

In a four-decade career, he wrote more than 500 articles and several books, including “Loneliness: Human Nature and the Need for Social Connection.”

Co-authored with William Patrick in 2008, the book presented Cacioppo’s theories on loneliness to a popular audience, describing the state of mind partly as a disease—it is contagious, inheritable and quite literally damaging to the heart and partly as a biological signal akin to hunger.

“His research on the causes and consequences of loneliness was rigorous, deep, and impactful,” Daniel Gilbert, a Harvard University psychology professor, wrote in an email. “Anyone who tells you that being lonely is as bad for your health as smoking a pack of cigarettes a day is quoting John Cacioppo without knowing it.”

Cacioppo was sometimes jokingly referred to as “Dr. Loneliness,” and his research coincided with, and perhaps to some extent spurred, a wave of international interest in the subject.