Few things are as costly as having one of your best employees resign. Too often, employers blame an employee’s exit on everything except the obvious, underlying reason.

“People don’t leave jobs; they leave managers,” says Travis Bradberry, coauthor of Emotional Intelligence 2.0. “Managers tend to blame their turnover problems on everything under the sun, while ignoring the crux of the matter. The sad thing is that this can easily be avoided. All that’s required is a new perspective and some extra effort on the manager’s part.”

Bradberry is cofounder of TalentSmart, a leading provider of emotional intelligence tests and training, serving more than 75% of Fortune 500 companies. In the following list, he offers the nine worst things managers do that send good people packing.

1. Overwork People
High expectations and deep personal involvement in the work one does can lead to burnout, and your best employees are likely to be highly committed to the work they do.

“Nothing burns good employees out quite like overworking them,” Bradberry says. “It’s so tempting to work your best people hard that managers frequently fall into this trap. Overworking good employees is perplexing; it makes them feel as if they’re being punished for great performance. Overworking employees is also counterproductive. New research from Stanford shows that productivity per hour declines sharply when the workweek exceeds 50 hours, and productivity drops off so much after 55 hours that you don’t get anything out of working more.”

If you must increase how much work your talented employees are doing, you’d better increase their status as well. Talented employees will take on a bigger workload, but they won’t stay if their job suffocates them in the process. Raises, promotions, and title-changes are all acceptable ways to increase workload. If you simply increase workload because people are talented, without changing a thing, they will seek another job that gives them what they deserve.

2. Failure to Recognize Contributions and Reward Good Work
It’s easy to underestimate the power of a pat on the back, especially with top performers who are intrinsically motivated. Everyone likes kudos, none more so than those who work hard and give their all. Managers need to communicate with their people to find out what makes them feel good (for some, it’s a raise; for others, it’s public recognition) and then reward them for a job well done.

“Of employees who leave a company, 5 to 10% do so because of money; of the remaining 90 to 95%, many leave because they don’t feel they are being recognized,” write George Manning and Kent Curtis in The Art of Leadership.

“Better alignment of employee-reward preferences with a company’s human capital strategy directly translates into measurable ROI gains,” Richard Kantor, a partner in AON Hewitt, says. “You can start talking to people differently and shine a spotlight on the parts of a reward program that are most important to them. It builds trust by helping individuals to see their possibilities.”

3. They Don’t Care about Their Employees
More than half of people who leave their jobs do so because of their relationship with their boss. Smart companies make certain their managers know how to balance being professional with being human. These are the bosses who celebrate an employee’s success, empathize with those going through hard times, and challenge people, even when it hurts. Bosses who fail to really care will always have high turnover rates. It’s impossible to work for someone eight-plus hours a day when they aren’t personally involved and don’t care about anything other than your production yield.

“Imagine the benefits for work of being skilled in the basic emotional competencies – being attuned to the feelings of those we deal with, being able to handle disagreements so they do not escalate, having the ability to get into flow states while doing our work,” writes Daniel Goleman, author of the groundbreaking book, Emotional Intelligence. “Leadership is not domination, but the art of persuading people to work toward a common goal.”

 4. They Don’t Honor Their Commitments
Making promises to people places you on the fine line that lies between making them very happy and watching them walk out the door. When you uphold a commitment, you grow in the eyes of your employees because you prove yourself to be trustworthy and honorable (two very important qualities in a boss). But when you disregard your commitment, you come across as slimy, uncaring, and disrespectful. After all, if the boss doesn’t honor his or her commitments, why should everyone else?

“A commitment to basic values such as honesty and responsibility is crucial for building trust, and trust is the bedrock of organizational survival and growth over the long term,” write Manning and Curtis.

5. They Hire and Promote the Wrong People
Good, hard-working employees want to work with like-minded professionals, says Bradberry. When managers don’t do the hard work of hiring good people, it’s a major demotivator for those stuck working alongside them.

“Promoting the wrong people is even worse,” he says. “When you work your tail off only to get passed over for a promotion that’s given to someone who glad-handed their way to the top, it’s a massive insult. No wonder it makes good people leave.”

6. They Don’t Let People Pursue Their Passions
Talented employees are passionate. Providing opportunities for them to pursue their passions improves their productivity and job satisfaction. But many managers want people to work within a little box. These managers fear that productivity will decline if they let people expand their focus and pursue their passions. This fear is unfounded. Studies show that people who are able to pursue their passions at work experience flow, a euphoric state of mind that is five times more productive than the norm.

7. Failure to Develop People’s Skills
Good managers manage, no matter how talented the employee. They pay attention and are constantly listening and giving feedback. The sixth century Chinese philosopher Lao-tzu said, “Leadership is service, not selfishness. The leader grows more and lasts longer by placing the well-being of all above the well-being of self. Through service to others, the leader becomes strong.”

Management may have a beginning, but it certainly has no end, Bradberry believes. “When you have a talented employee, it’s up to you to keep finding areas in which they can improve to expand their skill set. The most talented employees want feedback—more so than the less talented ones—and it’s your job to keep it coming. If you don’t, your best people will grow bored and complacent.”

8. Failure to Engage Their Creativity
“The most talented employees seek to improve everything they touch,” says Bradberry. “If you take away their ability to change and improve things because you’re only comfortable with the status quo, this makes them hate their jobs. Caging up this innate desire to create not only limits them, it limits you.”

9. Failure to Challenge People Intellectually
Great bosses challenge their employees to accomplish things that seem inconceivable at first. Instead of setting mundane, incremental goals, they set lofty goals that push people out of their comfort zones without setting unreasonable goals. Then, good managers do everything in their power to help them succeed. When talented and intelligent people find themselves doing things that are too easy or boring, they seek other jobs that will challenge their intellects.

Bringing It All Together
If you want your best people to stay, you need to think carefully about how you treat them.

“Businesses must find a way to help managers understand the people with whom they work, “Kantor says. “It’s not about being manipulative – it’s about being smart and helpful. Some managers are intuitively good at this.”

“While good employees are as tough as nails, their talent gives them an abundance of options,” Bradberry says. “You need to make them want to work for you.”