Others have already made the business case for humility quite compellingly. Jim Collins defined his “level 5” leader as someone with the powerful combination of personal humility and professional will, and Patrick Lencioni has listed humility as one of three characteristics of his “ideal team player.” Of course, believing that humility is important is one thing. Identifying it is something else.

In their excellent book The Spirituality of Imperfection, Ernest Kurtz and Katherine Ketcham dedicate a chapter to this often misunderstood and unpopular virtue. In the modern era, they write, words like “lowly” call to mind “servility and self-abasement, ‘meek’ is equated with cowardly submissiveness, and ‘mildness’ is interpreted as blandness.” That’s certainly a distorted view of this virtue.

“Humility” comes from humus, the Latin word for “soil.” It suggests being grounded. It means being in touch with reality. It is truthfulness, first and foremost with ourselves and about ourselves—with the good, the bad, and the ugly about ourselves. One of my teachers once defined humility as being “right-sized” before the other, neither too big nor too small. Another taught me that humility is not being self-conscious. Humility enables a person to be more attentive and present to another.

So how can one identify those humble people, who make ideal team players and have the potential to become level 5 leaders? There are some obvious answers, like watching out for the red flags of grandiosity or narcissism. Here are a few other characteristics to notice:

They don’t compare themselves to others. In addition to being the “thief of happiness,”  comparison is an indicator of humility’s absence. If you’re asking a humble job candidate questions that require him to compare himself with others, be prepared for him to be a bit baffled, slow, and perhaps unimpressive in his response. Because he doesn’t have a lot of practice with comparison, he’s not very good at it. We hear about the “war for talent” and the search for exceptionally good workers. Humility adds a paradoxical twist to this search: we want exceptionally competent people who are convinced that they are unexceptional.

They don’t realize they are humble. This is perhaps the central paradox of humility: if you think you have it, you don’t, and if you really have it, you’re unaware that you do. If you want the people around you to have a better chance of retaining humility, don’t make them aware that they have it.

They are aware of their own defects and shortcomings. But they also have a serenity and peace about those defects and shortcomings that doesn’t detract from confidence in their abilities, strengths, or talents. Asking a potential associate about her defects, shortcomings, or failures is one of the best ways to gauge her humility and and to learn other important aspects of her character.

There’s one more very important way to identify this quality of great team players and superb leaders. Since we tend to see the world not as it is but as we are, the best way to sharpen our vision for the humble is to become more humble ourselves.