Q. You are in a bad mood. What effect could this have at work?

A. Research confirms that a bad mood can impair your ability to work, and it can spread to others around you. You can “catch” bad moods without even knowing it, and that is what makes them so insidious, said Sigal Barsade, an associate management professor at the Wharton School of the University of Pennsylvania.

Q. How do you catch a bad mood?

A. Professor Barsade has done studies on emotional contagion that show that we unconsciously mimic the expressions and demeanour of those around us, along with the moods behind them. We may be oblivious to the effect, “but it still influences how we think and what we do,” she said. Fortunately, good moods are also contagious, she has found. So the clichés that you should put on a happy face and let a smile be your umbrella actually have some validity.

Q. How can moods affect decision-making?

A. In an exercise, professor Barsade analysed four groups of people who were asked to distribute a limited amount of bonus money. Unknown to the other participants, an actor was assigned to display a different mood in each group.

When the actor showed high negativity — by frowning, raising his voice or tapping his pencil impatiently, for example — the group was much less likely to be cooperative and more likely to engage in conflict, professor Barsade found. But in the groups where the actor displayed a positive response — say, by smiling and leaning forward — participants were more cooperative in allocating the money, she said. The actor’s moods spread to others and influenced their actions, she found, but they were mostly unaware that this had happened.

Q. Can a bad mood serve a good purpose?

A. Yes, according to Jennifer M. George, a management professor at Rice University, positive moods are better for promoting confidence, creativity and new ideas, but negative moods can be good for focusing on the work at hand and getting it done. That is because people in bad moods tend to be more realistic, more self-critical and more attuned to detail, she said.

Both positive and negative moods are needed to work effectively, George maintains. As moods inevitably fluctuate throughout the day, the best workers — and their managers — know how to harness that energy, she said.

Moods are also important signals. Some moods originate in an argument at home or in a fleeting irritation; others have a cause that is directly related to work. “If everyone in a workplace is in a bad mood, maybe it’s a signal that there’s something wrong there,” George said. On the other hand, if you are the only one in a bad mood, and it lasts a long time, that may be a signal that the problem lies within yourself, and that you need to seek help.

Q. Are some moods worse than others — and how can you tell?

A. Daniel Goleman, a psychologist and author of Emotional Intelligence and Social Intelligence, says that it is important to know which bad moods are harmful and which are just a part of life. “The bad moods that really hurt are the ones where you obsess and ruminate about what it is that’s upset you so much,” he said. At that point, a part of the brain called the amygdala becomes overly active, to the point that you cannot focus on a task.

Q. What steps can you take to minimise the negative impact of a bad mood?

A. Self-awareness is the first step, researchers say. If you fail to be aware of your moods and those of others, you are more likely to do something — like sending an over-the-top e-mail message or yelling at a co-worker — that you will regret and that could even damage your career.

Goleman and others stress that moods have a biological component. Simple calming strategies like meditating, taking a walk or exercising have a physical effect on brain activity and may correct the neural circuitry that caused a bad mood to emerge. But if anger, anxiety or depression continue for days or weeks, they may be symptoms of a chronic disorder and a signal to seek help.

Q. Is it better to express your bad mood or to keep it inside?

A. One quick way to cope with a bad mood is to express it to co-workers you like and trust. A more effective way to handle a bad mood, Druskat said, is to step back and remind yourself of a higher purpose for being in your job — the parts of it that hold the most meaning for you.

Q. Can your role at work make a difference in the effect of your bad mood?

A. Definitely. Studies have shown that the mood of a team’s leader has much more impact on performance than that of other workers. As Goleman said, that gives “a greater emotional responsibility to the person who’s running things”. It means that the best leaders are mindful of their own moods and the moods of others.