The answer may surprise you.

In his new book, Mean Men, author Mark Lipton makes a compelling case that a number of men with the “entrepreneurial personality” fit the profile of psychopaths. Seamlessly melding anecdotes, published reports, court evidence, and hard scientific data, Mean Men describes what the author calls “10 traits + T” that mark a certain breed of entrepreneur that puts their vision for success above the well-being of the people who work at, invest in, and do business with their companies.

And that number is on the rise, owing to the number of younger entrepreneurs who are in a position now to start their own organizations without starting at the bottom of a large corporation and working their way up, gaining the experiential management skills needed to get stuff done without doing it themselves and without getting the sharp corners knocked off.

Not every entrepreneur is a “mean man” – there are a good number of inspiring people leading start-ups that don’t fit this description. They share the same drive, the same passion for control, the same risk tolerance and self-confidence, the same traits as the “entrepreneurial personality.” The difference is that these leaders demonstrate empathy and they don’t cross a bright-line into a shadow zone where these good traits go bad.

And here’s the thing: you may not realize that you’ve been working with one of these “mean men.” They’re particularly good at charming people, at creating compelling visions, at winning people back to their sides – and yet they micromanage, they bully, they humiliate, they destroy others to make themselves feel bigger. They take credit for the good ideas and blame others for the bad ones. And they do it all in a way that makes you wonder… is it me?

Mean Men isn’t just an easy-to-read analysis of the bosses we love to hate, it’s a reality check: “mean men” don’t have very good track records of financial success. They’ve fooled their boards, their congregations. They’ve fooled their employees, they’ve fooled us all with their big words and their jury-rigged results. But if you look at the photos, really look at them, the crowds just aren’t there.

It’s also a call to action: it includes things you can do individually, if you find yourself working with one of these destructive personalities; and it includes things we can do collectively as a community to set boundaries with these people and demonstrate that we will not accept their destructive leadership style. And we have to do it because, if we don’t, “mean men” contaminate the people around them, propagating the species. (I found this the most useful part of the book.)

I’ve worked with a lot of people over the last 35 years. I’ve worked with inspiring men and bullying men. I’ve worked with incompetent men and over-competent women. I’ve worked with condescending, cynical men, and with bat-shit, crazy women who shouldn’t have been allowed behind a wheel. I’ve worked with mentors and misogynists. I’ve worked with thousands of people, of all kinds.

But I’ve only worked with one person who meets the “mean man” criteria.

One was enough.