It takes years to build a great career but just months for a bad boss to destroy it. A manager who bullies and blames will spread insecurity wherever they go, with a drip-drip pattern of behavior designed to undermine all who stand in their path.

Over a third of America’s workforce has experienced abuse from their colleagues in the form of threats, humiliation or sabotage of performance. A further 75% of those who quit do so because of a difficult supervisor rather than the position itself.

The Workplace Bullying Institute has a list of the top 25 workplace bullying tactics and it’s pretty bleak reading. These include behaviours like singling out and isolating one person from co-workers; publicly displaying “gross,” undignified behaviour; abusing the evaluation process by lying about the person’s performance and even using confidential information about a person to humiliate privately or publicly. It ranges from the hard to identify to the outright aggressive.

But for those feeling rundown by overbearing managers, there’s light at the end of the tunnel. New research indicates that abusive bosses are their own worst enemy in the workplace.