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This is the most dangerous type of colleague, says Harvard

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Teamwork makes the dream work – most of the time.

Most workers will know at least one coworker they don’t like, whether they’re gossipy, lazy or controlling.

But according to a Harvard Business School study, these aren’t the worst traits to watch out for in a coworker.

Rather, it’s workers who display “toxic” behaviours that we need to look out for.

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This is a worker who “engages in behaviour that is harmful to an organisation, including either its property or people”, the report said.

They have a need to spread negativity, don’t care about the company’s performance and bully other workers. Toxic workers are the most dangerous for both performance and mental health.

As the report’s co-authors, Michael Housman and Dylan Minor, explained, the behaviour of toxic workers is both harmful and infectious.

“Toxic behavior can cause major organizational cost, including customer loss, loss of employee morale, increased turnover, and loss of legitimacy among important external stakeholders,” they wrote.

They added that exposure to toxicity can also lead to more toxic behaviour in other workers.

However, toxic workers on the whole tend to be more productive, selfish and can be overconfident.

But such staff members are also more likely to believe that the rules should never be broken.

Toxic workers cost more than hiring superstars

But the overall organisation cost of toxic workers to staff morale and turnover means that identifying and avoiding toxic coworkers actually has a significantly higher pay-off than hiring “superstar” employees.

The study put the benefit of a superstar performer at US$5,300. But terminating the employment, or addressing the behaviour of a toxic employee delivers companies savings of up to US$12,500.

“Even if a firm could replace an average worker with one who performs 20 in the top 1 per cent; it would still be better off by replacing a toxic worker with an average worker by more than two-to-one,” the report said.

In an interview with the Harvard Gazette, Minor explained that most human resources teams focus on finding the best performers at the risk of letting through a confident and productive, yet toxic staff member.

“As it turns out, we’ve all had personal experiences where we have a worker on the other side of the distribution [who], rather than really helping performance, actually hurt performance in one way or another.”

He said he’s often asked why any firm would have toxic staff.

“But then you realise they’re incredibly productive. And so, it makes sense then that maybe managers would look the other way because they’re really hitting all their productivity numbers.”

His advice? Do something about it.

The worst thing businesses can do is look away, as toxic behaviour has a propensity to spread. Companies need to terminate or reform the bad behaviours.

They also need to take care not to hire toxic staff – which means looking beyond productivity.

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