Why the jokes shouldn't be on David Brent

But bosses were yesterday warned against playing the joker themselves.

Business school researchers said cracking gags like David Brent - the Ricky Gervais character from The Office - can alienate staff and customers.

It can also erode a boss's authority, weaken their credibility and potentially distract from important work issues.

The study - from Long Island University, New York - was aimed at establishing an "analytical understanding of humorous interaction" among workers.

The key finding, according to the report's author, Jim Lyttle, was that bosses should hold back from being a full-time office clown because they will lose respect and not be taken seriously when they want to be.

Managers should, however, be prepared to see the funny side and avoid looking too stern in order to appear more accessible.

Jokes at the expense of individuals are taboo in case the victim decides to take the matter to an employment tribunal.

Mr Little said humour had its place at work: "It can provide such benefits as stress relief, team unification, employee motivation, idea generation and frustration diffusion through venting."

But he added: "Humour can distract us from the job at hand, hurt our credibility, or cause offence in increasingly diverse work settings.

"In the midst of this complicated situation stand managers, who occupy a position of responsibility for both the good and bad effects of humour in the workplace."

The report was published in the journal, Business Horizons.

A spokesman for its publishers, Elsevier, said: "No one denies that humour in the workplace can have tremendous benefits, ranging from stress relief, to team bonding, to idea generation, to just pure fun.

"But caution is advised. After all, whenever humour is involved, there is the possibility of causing offence.

"And when the person we offend is a boss, customer, or member of a minority group, the consequences for the company could be disastrous.

"Those managers out there tempted to model themselves along the lines of the David Brent School of Management would be advised to pay close attention to the advice in Lyttle's article.

"The message managers should take to heart is that humour should be encouraged and celebrated in the workplace."

The guide to office humour also advised against sarcastic humour that comes across as negative, insensitive or judgmental.

TOP TIPS FOR BOSSES

• Make yourself the butt of the joke occasionally to make you seem more open and approachable

• Avoid being cast as the "office clown" -avoid exhibitionism at the Christmas party

• Make sure staff are laughing at your jokes and not just because you are their boss

• Think twice before sending that "funny" email to everyone in the office

• Gentle chastisement is fine occasionally as a tool to motivate others

• Avoid sarcastic humour that appears negative, insensitive or judgmental

• Steer clear of death, religion and other topics than can cause offence or be misinterpreted

• Avoid put-downs. Repeatedly highlighting employees' shortcomings can lead to a tribunal