The Encyclopedia of Interactive Performance

Fingers and feet become involuntarily active when players feel on the spot. Fidgeting fingers and feet show up in exercises like Firing line and Hot seat. If you notice this behavior in yourself, breathe deep, relax your face, and respond without judgment.

When thinking fingers (or feet) show up in spect-actors, make physical contact with them. The connection grounds them and makes it easier for spects to respond more freely.