One of your most esteemed colleagues was recently promoted to management. You and others were happy for him, well, until you realized he turned into someone you never expected: A selfish and arrogant jerk.

What the hell happened?

You just witnessed Power Poisoning at work, a behavioral change observed again and again once a person rises to a position of power. Occuring independently of that individual's personality, it happens. And when it does, included are people previously considered "nice" and "caring." So what are the specific behavioral changes? Well, at least these three:

1. They become selfish and self-absorbed.
2. They start seeing others as a pure means to an end.
3. They tend to act like the rules don't apply to them.

It is dis-inhibition at the very root. It's not that people put in power become suddenly Machiavellian, it's just that they stop trying to control their bad behavior and impulses. In Gruenfeld's Cookie experiment, a group of students is given a temporary, artificial power structure and an assignment. Then, while working on that assignment, researchers "casually" bring them a plate of cookies. It is observed again and again that the "manager" in the group is likely to display uninhibited behavior, like eating more than his share, chewing with his mouth wide open and scattering crumbs all over the place.

A large body of empirical evidence shows that even a little bit of power is likely to corrupt. But while it is to a large degree a predictable phenomenon, it is hardly an incurable disease. To minimize the damaging effects of Power Poisoning, here are a few suggestions:

• Make your organization as hierarchically flat as possible.
• Train managers to be better at their jobs.
• Establish checks and balances to provide protection from power abuse.

Of course, it is quite possible that your toxic boss finally has a moment of clarity and pulls himself together to become a better leader. But don't count on it.

Further readings:

• "Good Boss, Bad Boss", Robert Sutton, Stanford Engineering School
• "The No Asshole Rule: Building a Civilized Workplace and Surviving One That Isn't,"  Robert Sutton
• "The Psychology of Power," Deborah Gruenfeld, Stanford University
• "Power, Approach and Inhibition," K. Dacher, D. Gruenfield & C. Anderson in the Psychological Review