What is the essential quality that moves a leader from merely mediocre to truly exceptional? The answer, according to science, probably isn't what you expect.

Forget confidence, decisiveness, or even intelligence (though those are nice to have, of course). The key to great leadership appears to be humility.

For example, one recent study found that, "CEOs who were humble were more likely to empower the top management team, which in turn enabled the management team to be better integrated. The empowering organizational climate then trickled down through the middle managers which increased their job performance, commitment and engagement with work." Other research has confirmed those findings.

What's less clear from this science is what exactly you should do about this reality. Can humility be cultivated and, if so, how?

The answer, according to a recent post from UC Berkeley's Greater Good Science Center, which studies positive psychology, is absolutely! A recent article by the Center's Vicki Zakrzewski provides a deep dive into the benefits of humility and also offers three science-validated tips for those looking to become more humble

1. Embrace your humanity (warts and all).

Humility and a healthy understanding of human frailty -- both your own and other people's -- goes hand in hand. The truly humble understand that no one's perfect and failure isn't the same thing as worthlessness.

"For many, when we fail at something that is important to us--a job or a relationship, for example--our self-esteem plummets because we tied our self-worth to those things. All of a sudden, we become bad or unworthy people, and it can be a long road to recovery," explains Zakrzewski. "Not so for people with humility... their ability to withstand failure or criticism comes from their sense of intrinsic value of being human rather than outer means. So when they fail at a task or don't live up to expectations, it doesn't mean that there is something wrong with them. It just means that they are human like the rest of us."

How do you get this sense of intrinsic worth despite the occasional screw up? A happy and secure childhood helps, but as no time machines are currently available, you can also work on this aspect of humility by cultivating "healthy adult relationships, such as friends, romantic partners, or even with a higher power. This recent GGSC article suggests some ways."

2. Practice mindfulness.

If the first route to greater humility requires some psychological heavy lifting, this next tip is more actionable -- just start a meditation or other mindfulness practice (it's probably much easier than you ever suspected).

"According to scientists, humble people have an accurate picture of themselves--both their faults and their gifts--which helps them to see what might need changing within. Mindfulness grows our self-awareness by giving us permission to stop and notice our thoughts and emotions without judgment," writes Zakrzewski.

3. Say thank you.

Gratitude continues to be the secret to improving just about any psychological complaint, including this one. "Saying 'thank you' means that we recognize the gifts that come into our lives and, as a result, acknowledge the value of other people. Very simply, gratitude can make us less self-focused and more focused on those around us- a hallmark of humble people," claims Zakrzewski.

Simply writing letters of thanks to important people in your life (you don't even have to send them) or pausing to list a few things you're grateful for each day won't just make you happier, it'll also make you more humble, and therefore a better leader.