When a guy adjusts his cuffs or straightens his watch, it is the male analog of the more feminine nonverbal of the "Hair Adjust Behind the Ear" (HABE). Timothy Geithner, the U.S. Secretary of Treasury, is certainly an alpha male - but from time to time, even alphas need to dial it up a notch. The cuff or watch adjust is a body language signal showing that, in the moment, the psyche is attempting to be more assertive. The emotional tone is one of "assertive-anxiety". Of course, the shirt cuff and a watch occasionally need adjusting, but the vast majority of time when men perform these gestures - they feel the need to be a less beta and a little more alpha. Certainly beta males will exhibit this and other "up-shifting" nonverbal behaviors more than alphas. It's not a measure of the person's overall personality, rather what the emotional brain is feeling in that moment.
See also: Secret # 1411: Dialing Up Her Alpha - Dana Perino
See also: Secret # 1209: Even Putin Has Anxiety - False Tie Adjust