“So outside of the laboratory, you might observe their behavior for yourself; humble people are relatively down-to-earth, intellectually open-minded, less focused on themselves, and have a relatively accurate view of their own abilities. Then, given recent research on humility, you might look at some of their outcomes to verify your hunch. Humble people have been found to be more helpful, more successful in the workplace, and more forgiving and thankful.”
I snagged his excerpt from this study:
http://www.scienceandreligiontoday.com/2012/01/05/how-can-you-tell-how-humble-someone-is/