Rainmakers fighting among themselves for clients feed a whole genre of film and television, including The Good Wife (for law) and House of Lies (for consulting), full of back-stabbing professionals politicking for superiority in an atmosphere of mutual mistrust. Collaboration, by definition, makes for poor drama. But it does yield excellent results, according to a study of a range of professions, by Heidi Gardner of Harvard Law School. Summarising the work in the latest Harvard Business Review, she writes that when specialists work together across their areas of expertise, their employers “earn higher margins, inspire greater client loyalty and gain a competitive edge”.

As the caricature consultants in House of Lies might say: “What’s not to like?” Plenty, in fact. Getting specialists out of their own silos is hard enough; persuading their fellow partners to let them into theirs even harder. Making collaboration work also requires professionals to pay more attention to what my bureau chief colleague decided to ignore: management.

Professional services groups try to project an image of collaborative harmony to the outside world. But Prof Gardner says 23 groups have invited her to talk about her work in the past six months because their leaders said they were struggling to persuade partners to share their expertise.

“I don’t want it to come across as though these people are complete assholes, just looking after themselves,” Prof Gardner told me last week. “They’re legitimately primed to think in this way.”

Short-term incentives, such as bonuses based on how much income individuals generate, or how many clients they acquire, skew behaviour towards the selfish. The hassle of getting together with colleagues is simply not worth most partners’ while. Many groups favour “the rock star, not the whole band”, as one person interviewed for the Harvard study said.

Even if professional services firms can convince individuals to work together, the sight of more than one partner in the room can spook clients, who may suspect they are being cross-sold more expensive partner time. To overcome this hurdle, the lawyers or accountants really have to agree to absorb the short-term cost. Once the benefits of collaboration start to become clear, including the payback to partners when they share leads with colleagues (mapped by Prof Gardner), objections raised by customers and senior professionals should fall away.

In research published in 2013, Laura Empson of Cass Business School described one firm that claimed to have achieved such seamless co-operation between partners, partly by using the recruitment process to reinforce the need for collaboration, partly by paying partners on a “lockstep model” by seniority, regardless of performance. One partner memorably likened the culture to “the Borg”, an alien race in the Star Trek series: “The Borg is a collective. They are this mass of things that go forward. If bits drop off, like limbs and heads, it’s completely replaced. And that’s us.”

But at less cult-like organisations, leaders have to work harder to achieve such a state, weeding out toxic candidates for partnership before they pollute the culture, reducing friction that impedes co-operation, restructuring pay and bonuses, and underlining the value of cross-disciplinary work.

Easier said than done. Partners still prefer client work to leading, while outside managers lack influence. One partner damned them to Prof Empson as “functionaries”, adding faint praise: “That’s not to denigrate [them] because they are very talented . . . but culturally we have a snobbery about lawyers being superior.”

Such ingrained attitudes are hard to break. As one person with 32 years of consulting experience has written in an online comment on Prof Gardner’s suggestion that leaders should turn away selfish rainmakers: “Yeah, right.”