In many companies, losing great talent isn't hard, unfortunately. You probably know the typical reasons why valuable employees leave --a terrible boss, being underpaid, feeling disrespected, simply getting a better opportunity-- but the more silently sinister signs warrant attention too.

I interviewed many talented employees for my book Find the Fire on what made them leave their previous job. I heard plenty of the above, but what stuck out were stories of quieter behaviors, assumptions, and norms embedded into a workplace that great talent couldn't leave behind fast enough.

Here, I'll share the 11 most frequently mentioned, unwritten, unwanted reasons that I noticed from my research. And they're hardly unavoidable. 

1. You'll get promoted, if you fit the profile.

Employees notice who gets promoted and they obsess over it. If those who get elevated all fit a specific, too-much-like-the-boss, non-diverse profile, it won't sit well. I'm not saying leaders shouldn't have an identified type to promote that exudes certain skills, traits, or values. They should, and be clear about the criteria.

I'm talking about blatant bias and disregard for diversity on multiple fronts entering the picture --which means talented employees will exit the picture.

2. It's okay to take risks, until one goes wrong.

When a leader talks up and encourages risk taking, but then skewers people who took a risk and failed, it's like talent repellent.

Instead, establish clear rules for risk taking, like what constitutes a good or bad risk, what happens with success or failure from a risk, who needs to approve a risk, etc. Then make the words match the pictures by rewarding healthy risk taking.

3. You can speak up, just don't speak out.

This means employees can and should stand up and voice their opinion, as long as it's the same as the bosses. A boss who encourages everyone to speak their mind but doesn't react well to dissention of opinion is high-grade poison.

4. "More with less" is the constant default.

"Do more with less" is the cry of today's resource strapped companies. However, a "more with less" mentality will wear your people down fast. Play this tape when it's truly warranted, but it can't be on a continual loop.

Sometimes you've got to do more with more --more resources, time, or money. I'm all for efficiency, but constantly assuming your best employees can deliver more with less will more or less mean they're gone.

5. If the boss doesn't see you, you must not be working.

I had a boss with an old school point of view on remote work: out of sight equaled out of mind, and out of luck for the employee because the assumption was that work wasn't happening. Today's leader simply must embrace at least occasional remote work --it's what employees want and where we're headed. Enough other companies are crafting flexible work that it's a hiring and retention competitive disadvantage to not embrace it.

6. You'll get ahead if you leave others behind.

Some workplaces reek of the politics, backstabbing and self-promoting behavior that becomes an unwritten success manual. Collaborative cultures count, and the absence thereof will send valuable employees scrambling.

7. Learning and growth is up to you.

You can't always be in harvest mode, never taking time to plant seeds, reflect, to provide learning and growth opportunities. You can't just sprint from sales quarter to sales quarter without making deposits in your people. Not showing employees you care about feeding their personal growth means they'll be hungry to look for someone who does.

8. I don't get positive feedback so you won't either.

Maybe that curmudgeon of a boss has a curmudgeon of a boss. The lack of appreciation flows downhill, becomes the norm, and makes rewarding and recognizing someone feel out of place and unwarranted. If you want great talent to walk out of the company, never thank them for the work they do in the company.

9. Ineptitude goes unaddressed.

Talented people get ultra-frustrated when dead weight goes unaddressed. The slackers that still draw a paycheck every day will gnaw at the high-flier who values a sense of fairness and wants to be surrounded with fellow A-players. Leave the rotten apple laying there and your best employees will leave the orchard.

10. We trust, but verify.

This is code for not only micromanaging, but the worst kind of it; leaders who say they're granting autonomy but are constantly checking-in, following up, making suggestions, asking for reviews. Micromanaging means talented employees will macro-leave.

11. If you're awake, you're at work.

In this device driven, global work world it's easy to never shut down. It's just as easy to find bosses who never actually do, and expect you not to either. Know when enough is enough or great talent will say "that's enough."