The science is pretty clear, some professions have more psychopaths than others, and sorry business leaders, you're at the top of the list. One study even found CEOs are three times more likely to be psychopaths than the average person on the street. 

Why is that? One explanation is that those who have psychopathic tendencies -- i.e. people with limited empathy who enjoy asserting their power -- tend to choose careers where wielding power and being a little ruthless are part of the gig. This hypothesis seems to be backed up by studies showing those with psychopathic tendencies are drawn towards business and economics majors in college.

But a new study suggests an alternate explanation might be part of the story too. The review of previous research on the topic recently published in the Journal of Applied Psychology found that being a bit of a psychopath actually helps you get promoted into leadership -- at least if you're a man.

The paradox for companies

This means that even if an average number of psychopaths enter business careers, by selecting for psychopathic traits when doling out promotions, companies ensure male psychopaths are overrepresented at the top. Women, who are stereotypically expected to be kind and nurturing, aren't rewarded for cold-blooded ambition at any stage in their careers, the research review confirmed.

So does that mean that once the slightly psychopathic (no one is suggesting chainsaw wielding lunatics are zipping up the corporate ladder here) reach the top, their cold bloodedness also helps them be effective leaders? Nope, says University of Alabama management professor Peter Harms.

"Overall, although there is no positive or negative relation to a company's bottom line when psychopathic tendencies are present in organizational leaders, their subordinates will still hate them," Harms commented. "So we can probably assume they behave in a manner that is noxious and whatever threats they make to 'motivate' workers don't really pay off." 

That presents a big paradox for companies: a little bit of evilness seems to be effective for clawing your way to the top, but it's lousy for being an effective leader once you get there.

Yet another reason not to promote jerks

The logical conclusion of these findings is that companies may want to redouble their efforts to avoid promoting ruthless performers. Yes, those great sales numbers might be appealing when you're considering whether to advance that regional head to the national position, but if the guy got them by stomping over co-workers and basic human decency, he's going to poison your culture once he reaches senior leadership.

Harms is blunt in his warning for businesses. "We should be more aware of and less tolerant of bad behavior in men," he said. "It is not OK to lie, cheat, steal and hurt others whether it is in the pursuit of personal ambition, organizational demands or just for fun."

Or to be even more direct: it might be tempting to promote that jerk, but you're really, really, really going to regret it one day.