When you log into Slack or tap your security card on the office turn style, do you do it with a spring in your step and a smile on your face? Do you wave a cheery hello, be it emoji or with real fingers, to everyone you pass? Or do you enter work mode with fear in your heart and a bone weary dread, keeping your eyes firmly fixed on the floor to avoid eye contact? If it’s the latter, you’re not alone, and chances are you’re suffering from a common condition that afflicts many people around the world. You don’t know what kind of mood your boss is going to be in today. It’s not you, it’s them.

There are good managers, who behave ethically most of the time, and there are bad managers, who don’t. And then there are the unpredictable “Jekyll and Hyde” managers, who are sometimes worthy of respect and other times abusive. In a study recently published in the Journal of Applied Psychology, a group of researchers working around the world described Jekyll and Hyde managers as being demoralising and likely to affect productivity as out-and-out abusers.