As CEO, all the scary scenarios that could sink your company can keep you awake at night. But what's your greatest fear, and how do you think it affects your ability to effectively lead a successful company?

Your fears and anxieties can hurt your productivity and decision making. In Harvard Business Review, Roger Jones, chief executive of London-based executive performance consulting firm Vantage Hill Partners, writes about a study he conducted of 116 CEOs and other executives' most deep-seated fears, and exactly how those fears affect their business.

"While few executives talk about them, deep and uncontrolled private fears can spur defensive behaviors that undermine how they and their colleagues set and execute company strategy," Jones writes.

The No. 1 fear of the CEOs and executives Jones surveyed was "being found to be incompetent." The impostor syndrome, he says, "diminishes their confidence and undermines relationships with other executives."

After the fear of being incompetent, the most common fears, in order, are: underachieving, appearing too vulnerable, being politically attacked by colleagues, and appearing foolish. What effect do these fears have? Underachieving, Jones says, "can sometimes make [you] take bad risks to overcompensate." The fear of being politically attacked can cause you "to be mistrustful and overcautious," while the fear of appearing foolish can inhibit your ability to "speak up or have honest conversations."

Additionally, about 60 percent of the leaders surveyed said the top three fears were present in them and their executive team and affected their teams' behaviors negatively. The top five fears combined, Jones says, perpetuated "a lack of honest conversations, too much political game playing, [and] silo thinking" among the executives.

The survey respondents admitted those behaviors resulted in a number of negative consequences. The most common were "poor decision making, focusing on survival rather than growth, inducing bad behavior at the next level down, and failing to act unless there's a crisis," Jones writes.

In additional interviews with 27 of the CEOs, Jones found that death--both literal and figurative--was also a big fear. The fear of professional and literal death "inspires a fixation on status, appearing youthful, and making money." Jones says the fear of dying or retiring made most CEOs think selfishly and make decisions that helped them financially, but hurt the company.

What can you do to combat your deepest fears and make sure the repercussions don't negatively impact your company? Jones says it's about awareness of what your own and what your colleagues' and employees' fears are, and being committed to weeding out self-interested behavior.

When you're looking for executives to hire, make sure to focus on emotional intelligence. Jones says you should foster a culture where no one is afraid to speak his or her mind. As for team bonding, you can hold offsite programs where you and your executives can share your fears and experiences. It may sound a bit touchy-feely, but fear shuts off lines of communication and erodes trust. The key is to make sure you are not being run by fear, and to make sure your executives and employees trust each other.