[P1_aka_P1]

I was fascinated by the Hood hands during the Foley discourse, particularly the thumbs, especially the left thumb. Watch carefully throughout, then consider the Foley hands in the infamous 'Flaperon' photograph. Interesting stuff.

Perhaps the primer – HERE - may assist the beginner, about halfway down. "hands clenched together":-

Summary.

The thumbs have been used as a sign of power and authority for thousands of years. In Roman times, the thumb held up or down meant life or death to a gladiator. Even without any training, others intuitively decode thumb signals and seem to understand their meaning. You are now in a position not only to decode thumb signs, but to train yourself to use them