Most companies have four basic archetypes among their staff: the competent jerk, the lovable fool, the lovable star and the incompetent jerk.

The competent jerk is someone who knows a lot but is very unpleasant to deal with. The lovable fool doesn't know much but is a delight to have around, the lovable star is both smart and likeable, and the incompetent jerk, well, that's self-explanatory.

So say authors Tiziana Casciaro and Miguel Sousa Lobo, writing in the Fall edition of Rotman, the magazine of the Rotman School of Management, University of Toronto, Canada.

Examining how informal social networks take shape in companies which have taken pains to recruit a variety of skills and personalities for its success, the authors say informal work relationships play a more vital role than most bosses realise or value.

They say their research shows that when people need help getting a job done, they will choose a congenial colleague over a more capable one.

There is a variety of reasons why people choose who they would like to work with, if given the choice.

Some pick the star performer as they feel there is prestige being associated with this worker. Others pick a strategically-placed superior in the hope this will later enhance their careers.

But in most cases, say the authors, people choose their work partners for two main reasons: job competence and likeability.

"Obviously, both things matter; less obvious is how much they matter," they say.

The authors studied four organisations - one which is profit-motivated, one non-profit, another large and the fourth, small.

No matter which organisation they studied, they found that everybody wanted to work with a lovable star and nobody wanted to work with an incompetent jerk.

They say things got more interesting when people faced the choice between competent jerks and lovable fools.

Ask any manager and he will obviously pick competence over likeability.

But, surprise, surprise, the two researchers found out that the reverse was true in the four companies they analysed.

They say: "Personal feelings played a more important role in forming work relationships - not friendships at work, but job-oriented friendships - than is commonly acknowledged, even more important than evaluations of competence."

They found out that if a colleague is strongly disliked, it's almost irrelevant whether or not, he or she is competent; people just won't work with such a person. Full stop.

By contrast, if someone is liked, his colleagues will seek out every little bit of competence he has to offer.

Say the authors: "And this tendency didn't exist only in extreme cases; it was true across the board. Generally speaking, a little extra likeability goes a longer way than a little extra competence in making someone a desirable work partner."

Although there are people who are liked by everyone, there are also ones who are liked by some and disliked by others. Social psychologists have long known that people with empathy for one another, who share same likes and dislikes and who have mutually attractive personalities will simply click in friendship. These are the people who like to work together.

The authors say: "Because you are relatively comfortable with people you know, you are likely to be more accepting of their differences."

But there are drawbacks. One is the limited range of perspectives that a homogeneous group often brings to bear on a problem.

"A diverse collection of people - whatever the tensions and misunderstandings that arise because of their differences - provides an array of perspectives that can lead to truly innovative approaches to accomplishing a task", say the authors.

They point out that working with the same old colleagues can also dampen debate: colleagues may hesitate to challenge or reject a bad idea from someone they know or like.

There is another danger: People who choose to work with those they like may have a good time in the office but they may get nothing done.

The authors point out that their essay is not about formal work relations ("You work with your boss whether you like him or not") but in workers' choices of informal, though work-related, interactions.

So, can a manager do anything to manufacture liking in the office milieu?

Yes, say the authors.

* Promote familiarity: Create an office area to foster informal water cooler-style chats. Have, say, a cocktail party before a project begins to get all involved to be more familiar with one another. Start an all-office Friday get-together.

* Get the likeable staff members to play the role of "affective hubs" in the office. Since they are liked by most colleagues, they can bridge gaps between diverse groups which might not otherwise interact. They may not be the best workers but they are valuable.

Such an individual should be put in a position to link people from different parts of the organisation who might otherwise never think of collaborating with one another.

* Work on the competent jerks. They represent a missed opportunity for the organisation because so much of their expertise goes untapped. His supervisor must provide aggressive coaching. For example, tick him off for bad behaviour immediately after the fact than wait for the year-end performance appraisal to do this.

In one case, the boss denied the competent jerk his promotion explaining to him why his behaviour was self-defeating. When his behaviour improved, he was promoted the next year.

Or such a jerk might be placed in a job which allows him to work independently.

Say the authors: "Too many managers fail to appreciate the benefits that a likeable person can offer an organisation, particularly if those benefits come at the expense of some measure of performance."

They stress that building an environment in which people like one another can help all employees work more happily and productively and encourage the formation of strong and smoothly functioning social networks.

Tiziana Casciaro is an assistant professor of Organizational Behaviour at Havard Business School and Miguel Sousa Lobo is an assistant professor of Decision Sciences at Duke University's Fuqua School of Business in Durham, North Carolina.