When it comes to effective leadership, success isn't solely determined by driving revenue or spearheading innovation or setting a clear vision for a company. Effective leadership results from something more -- a quality that is, often times, less visible and more difficult to carry out. Leaders who possess this, however, are the ones who achieve the greatest results.

That quality is self-awareness.

I've seen this to be true both in companies I admire and ones I've had the pleasure of working with directly. Leaders' ability to lead themselves is a key ingredient to success. Whether you are leading a movement, a company or a sales team, self-awareness is vital to your effectiveness as a leader.

Why self-awareness matters

In a study commissioned by leadership consultant Green Peak Partners, and conducted by Cornell University's School of Industrial and Labor Relations, researchers looked at 72 senior executives at public, venture-backed and private-equity sponsored companies and found that self-awareness was the biggest predictor of a CEO's overall success. In fact, hard-driving, "results-at-all-costs" executives actually hurt the bottom line, while self-aware leaders with strong interpersonal skills deliver better financial performance.

"This is not altogether surprising, as executives who are aware of their weaknesses are often better able to hire subordinates who perform well in categories in which the leader lacks acumen," the study notes. "These leaders are also more able to entertain the idea that someone on their team may have an idea that is even better than their own."

The trickle down effect

It makes sense that leaders with strong interpersonal skills would achieve greater results. After all, part of a good leader's job is to inspire employees to work toward the company's vision and initiatives.

But when executives experience difficulties outside the workplace, their ability to inspire is impacted, which can lead to undesirable results. Let's face it: if things at home aren't well, it's likely to affect your professional life. Conversely, if you're having a crappy day at the office, chances are it will seep into your personal life. Therefore, it's imperative that leaders learn to lead themselves. Otherwise, it will be difficult for them to lead others -- and that has a trickle-down effect in business.

"Leading with baggage is misleading," says leadership expert Yigal Adato. "If my employees are afraid that I'm not okay, they're going to be afraid that their jobs aren't secure. And they're going to treat the customers with fear as opposed to epic customer service."

Taking a time out

In my prior business, if a sales rep was having a bad day, I would encourage him to take a time out. Sometimes I would just say, "Look, go to a movie, go do something else, because you're not going to be effective with a client today if you don't have the right mindset."

Many times, reps looked at me quizzically wondering if I was serious or not; I was completely serious. I didn't want a sales rep getting on the phone with a client and possibly run the risk of upsetting that client. I'd much rather they go do something else, because, as a leader, I know that when you try to force yourself to have client interactions, something is likely to go awry.

If your non-verbal communication shows you've got some insecurity or worry, your client isn't necessarily going to chalk it up to something you've got going on at home. Instead, the client is going to suspect something is not right. They might not know what it is exactly, but they know something is off -- and they might decide to walk away from a deal as a result.

When the different parts of your life are not aligned, others can feel that. It shows up in both your professional and personal life. Having self-awareness means you can be a good leader to yourself by adjusting accordingly. And, ultimately, everyone wins.

It's Your Turn

How do you lead yourself and others? What qualities are necessary to be an effective leader? Share your thoughts on Twitter, LinkedIn, or in the comments.