1: The Back Hand. ‘I know I’ve said it before but I will say it again.’ Slap dominant hand into non-dominant hand. Use as a reinforcing gesture when critical opponent seems unresponsive.
2. The Dialectic: ‘This is a dialectic and I’m going to explain it.’ Grip imaginary six centimetre object between thumb and forefinger. Rotate wrist ninety degrees, snapping into end position. Smoothly rotate back to start. Repeat up to three times depending on conviction. Use when expressing a shift from one thing to another. Highly infectious.
3. The Tiny Dialectic. ‘I’m making a very fine distinction.’ Follow directions for ‘The Dialectic’ but with thumb and forefinger one centimetre apart. Bring hand toward eyes for closer inspection. Use when unpicking specific detail, or when too self-conscious to use ‘The Dialectic’ gesture.
Courtesy of: http://criticalhandgestures.tumblr.com/