Study authors Reed W. Larson of the University of Illinois and David M. Almeida at the University of Arizona at Tucson say that the repeated daily experience of secondhand emotions can travel from one person to another in a family. This may be a means by which parental distress, anger, or depression can lead to the same conditions in other family members, particularly children.

Professors Larsen and Almeida studied 450 families over three years. They peeked in on the activities, moods, and emotional lives of the study subjects through diaries and by calling to ask how they felt. Other families filled out questionnaires about the effect of secondhand emotions in their lives.

"The most consistent finding was that negative emotions can create a chain reaction of distress that moves through a family, affecting everybody's behavior and eventually, their well-being," says Dr. Almeida, a professor of family studies and human development. "These emotional spillovers also appear to follow the order of power in a family, from fathers to mothers to children."

The study also revealed that an emotion can be transformed from one person to another in its transmission. For instance, scorn in one person may induce shame in another. Anger in a powerful person can create anxiety in a less powerful family member.