It's common for the hand to come to the chin when we're making up our minds.

It’s common for the hand to come to the chin when we’re making up our minds.

Chin stroking, is another evaluative gesture which was made popular by movies, television shows and cartoons. The cliché says that the chin scratcher is old, wise and is bearded! Beard or chin stroking signifies that the decision making process has begun, but that a conclusion hasn’t yet been reached. What follows the chin scratch tells us exactly what to expect, be it a positive or negative outcome. When prompted for a final decision,
if the hand comes down and across the body at right angles it tells us that a negative answer will follow, but if the hand comes forward and is placed on the thighs in a ready posture or the arms remains uncrossed the answer will be positive.

Without conscious awareness the tongue makes an appearance under deep concentration usually by being protruded to the side. Tongue protrusion is an evolutionary throwaway gesture thought to have arisen as food rejection mechanism by infants. When it happens in adults it means they are genuinely focused on their task and wish not to be bothered by others, hence the rejection root. The tongue can also be seen moistening the lips more often when under stress or anxiety as the mouth dries up, or can be moved back and forth across the lips as a pacifying behaviour to sooth while under stress.