(CNN) -- Criticism from bosses can be hard to swallow. But research shows there are more constructive ways for managers to deliver negative feedback, and that bosses should use positive comments a lot more -- about six times more -- than criticism.
The study, done by the University of Michigan Business School several years ago, compared team performance to the frequency of praise and criticism given within the teams.
The best-performing teams used about six times as many positive comments for every negative one. It found that the worst performing teams, on average, used three negative comments for every positive one.
American psychologist, John Gottman, has found a similar ratio for positive and negative comments from spouses leading to happier marriages.
"Negative interactions tend to dampen the enthusiasm and commitment of the individual," says Jack Zenger, a leadership consultant, who was not part of the studies. "A manager should be very thoughtful and weigh the risks and benefits before giving any negative feedback."
While positive feedback seems to be more helpful in the work setting, leadership experts say the effectiveness of both praise and criticism as motivators has a lot to do with how the message is delivered.
When a manager must give negative feedback to a worker, it helps not to do it abruptly, Zenger says. Managers can preface the conversation by letting the employee know that his or her contributions are appreciated, and that a specific suggestion is a way to improve effectiveness and nothing more than that.
"When we watch a movie, there is often background music that signals to us whether something terrible is about to happen or whether this is a happy scene in the movie. Ideally, managers need to provide a similar signal that provides an accurate context for any message," he says.
Zenger adds that any criticism should be delivered in the utmost privacy, never in front of others.
Denmark-based Alexander Kjerulf, who studies happiness at work, said his organization conducted a survey that found lack of praise and recognition to be the No. 2 factor making people unhappy at their jobs. (The top reason was having coworkers who constantly complain.)
And even though the research shows it is unproductive to criticize more than praise, experts say it is still important to give negative feedback once in a while.
"Criticism is vitally important. We need to tell people what they do well and what they can do better," Kjerulf says. "But many workplaces either give no feedback or only give criticism. This is a shame because we learn so much from being told what we get right."
On the other end of the feedback spectrum, there are ways for praise to work better as a motivator.
Kjerulf says that praise, if delivered poorly, like when it seems obligatory or trivial, can have negative effects. "It makes us mistrust all future praise," he said.
For praise to be constructive, it needs to be specific and heartfelt, Zenger says.
"A passing 'good job' or 'well done' means very little. But when a manager takes the time to tell the individual specifically what he or she had done and the consequences that it has had, then praise begins to have an extremely positive effect," he says.
But while praise should be delivered with conviction or an emotional connection, emotions should be taken out of the equation when giving negative feedback, Zenger says. Delivering criticism while either party is angry, for example, is usually not constructive.
"When emotions become the dominant force and the quality of the ideas are taking a backseat, then feedback is given the wrong way," he says.
But managers should realize that feedback should go both ways: managers should seek feedback from their employees about their own behavior.
"The manager who asks, 'what can I do to be a more effective supervisor for you' is sending the signal that no one is expected to be perfect in that we can learn from each other," Zenger says. "How the manager responds to the employees' observations will serve as the example for how they respond to criticism."
But in the case where an employee is upset about negative comments from managers, "there's no way around it," Kjerulf says, "you'll have to talk to your boss. Be very specific and say what it is about the boss' behavior you don't like."