The thumb is probably one of the most important aspects of our body. We readily use it almost every second of the day. The palm has been closely tied with the development of the brain and the eye, but in terms of palmistry, the thumb deals a great deal with a person's will. The thumb reading is an important segment of palmistry based on thumb impression. Palmists determine a lot regarding the thinking ability and the mental power of an individual by reading his or her palm. A considerable part of the brain controls the movement of the thumb. So, the thumb movements are influenced by the thought process of the individual.