A pacifying behaviour. The person is soothing themselves in response to a stressor.

The neck is one of the most vulnerable parts of the body and one of the richest sites for self-soothing. Note what was said or shown in the seconds before the hand rose. Men tend to grip the front of the neck; women tend to touch the hollow at the base of the throat, sometimes called the suprasternal notch.

A scratch responding to an actual itch (usually brief, with no return). Pacifying behaviour lingers or repeats.