Is a bad mood contagious?
--Michael Lenneville, Washington, D.C.

Gary W. Lewandowski, Jr., associate professor of psychology at Monmouth University and co-editor of, provides an answer:

WHEN YOU SEE someone coughing, you reflexively know to steer clear of his or her germs. When you observe someone who is cranky or complaining, it is less obvious what to do. Studies suggest, however, that others' moods may be as easy to catch as their germs.

Psychologists call this phenomenon emotional contagion, a three-step process through which one person's feelings transfer to another person. The first stage involves nonconscious mimicry, during which individuals subtly copy one another's nonverbal cues, including posture, facial expressions and movements. In effect, seeing my frown makes you more likely to frown. People may then experience a feedback stage--because you frowned, you now feel sad. During the final contagion stage, individuals share their experiences until their emotions and behaviors become synchronized. Thus, when you encounter a co-worker on a bad day, you may unknowingly pick up your colleague's nonverbal behaviors and begin to morph into an unhappy state. Mimicry is not all bad, however; a person can also adopt a friend or colleague's good mood, which can help enhance their bond.

Although mimicry often occurs outside of our awareness, sometimes we can observe it. Let us say you see someone across from you on the train yawn. Often you cannot help but yawn as well. Recent research suggests that this type of mimicry is more common when the person yawning is someone close to you, such as a family member, good friend or romantic partner. Another study revealed that nonconscious mimicry, also dubbed the chameleon effect, occurs more often in more empathetic people.

The contagious nature of emotions can become amplified when individuals are in frequent contact with one another. In one study, marriage researchers Lisa A. Neff of the University of Texas at Austin and Benjamin R. Karney of the University of California, Los Angeles, examined more than 150 couples for three years to determine how one spouse's stress influences the other spouse and overall marital quality. They found that wives were not affected significantly. Husbands, however, experienced lower marital satisfaction when their wives reported higher stress. More important, emotional crossover was more pronounced when the couple engaged in negative conflict-resolution practices, such as rejecting or criticizing the partner.

These studies emphasize the importance of choosing wisely the company you keep, so you can catch others' good moods, rather than their bad moods.