While researching rural life more than 20 years ago, Paul C. Rosenblatt took his 12-year-old son with him to interview farm families in the Midwest. Father and son stayed in a farmhouse and had to share a bed.

“It was terrible,” said Dr. Rosenblatt, a professor of sociology at the University of Minnesota, Twin Cities, because his son thrashed and turned so much that “his feet were in my face all night.”

Tired and bedraggled the next day, he recalled thinking about how challenging it can be to adapt to sleeping with another person.

In more recent research — on grief — Dr. Rosenblatt interviewed couples whose children had died.

“They quite often would tell me that they dealt with their grief by holding each other and talking together in bed at night,” he said. “It seemed that I kept being reminded of how sharing a bed impacts our lives and sense of well-being.”