Did you know your thumbs have a status of their own? When we carry our thumbs in a "high" position (pointing up, gesturing outward, even placing two "thumbs up") are all indicators of high confidence and personal status. Placing hands in pockets with thumbs exposed demonstrates a perfect example of this innate confidence. Called a "gravity defying" gesture, it indicates you are feeling good about the present circumstances you find yourself in. 

 

from "What Every Body Is Saying", by Joseph Navarro