Name: Jekyll and Hyde managers.

Age: Robert Louis Stevenson’s novella, as you’ll know of course, was published in 1886. Since then, “Jekyll and Hyde” has been used to describe anyone who is sometimes a good egg and other times a very bad one. Including bosses.

Is that what this is about? Bosses? Correct. And a new study on the ones who yo-yo between being considerate and abusive.

Well, looking on the bright side, at least they’re not bad all the time, and there are ethical lulls (if not lols) between the storms. You’d think. But here’s the interesting thing: researchers at the Stevens Institute of Technology in New Jersey have discovered that it could be worse than a consistent tyrant.

Why is that? “If you’re constantly guessing which boss will turn up – the good cop or the bad cop – then you wind up emotionally exhausted, demoralised and unable to work to your full potential,” says Dr Jek … sorry, Dr Xu.

Who is he? Something to do with the NYPD? No. Dr Haoying Xu is the lead author of the study, which was published in the Journal of Applied Psychology, and found that employee performance and morale dropped significantly when bosses behave erratically.

Makes sense, having seen The Office. Both ours and theirs. Why is it worse, though? “Reverting to an ethical leadership style doesn’t magically erase the impact of prior bad behaviour,” Xu said, “and in some circumstances, it can actually make things worse.”

So it’s the unpredictability. But surely a consistently horrid boss isn’t great either? Plenty of studies have shown that bad management has serious consequences for companies. Although interestingly research from Aarhus …

… in the middle of our street. Shush. Aarhus University in Denmark found companies with narcissistic CEOs often performed better, but only if they were female bosses.

Fru Hyde? Possibly. Anyway, of the new research, Xu also said: “Organisations tend to intervene when bosses are consistently abusive, but are more tolerant of leaders whose abusive behaviour only shows from time to time.

So bad cop gets rooted out, while Dr Jekyll, Mr Hyde and Mrs H all stay. Exactly. And not only can intermittent bad behaviour be more toxic, it can also be contagious.

You can catch it? Dr Xu says that because employers tend to pick up their managers’ habits, including the bad ones, unpredictable bad behaviour from the boss could spread. “If that’s the case, then it would be another big reason for organisations to take Jekyll-and-Hyde leadership seriously.”

I will. So don’t say: “Ride out the bullying, he’ll probably bring cake tomorrow.”

Do say: “Hyde, you’re fired!”