Co-rumination: Frequent or obsessive discussion of a problem, usually among girls or women. The term was coined in 2002 by Dr. Amanda J. Rose, a psychologist at the University of Missouri, in a paper she wrote for the journal Child Development.
According to a recent article in the New York Times:
The behavior is typical among teens — Why didn’t he call? Should I break up with him? And, psychologists say, it has intensified significantly with e-mail, text messaging, instant messaging and Facebook. And in certain cases it can spin into a potentially contagious and unhealthy emotional angst, experts say.
Dr. Rose told the Times that "for boys, such intense emotional conversations, which tend to occur less often, did not contribute to heightened anxiety or depressive moods."
“When girls are talking about these problems, it probably feels good to get that level of support and validation,” said Dr. Rose, whose latest study on co-rumination was published in the journal Developmental Psychology last year. “But they are not putting two and two together, that actually this excessive talking can make them feel worse.”
Ruminate—to turn a matter over and over in the mind—has a second meaning of "to chew cud." A ruminant is any hoofed mammal with a rumen, a specialized portion of the stomach that returns the cud to the mouth.