Stiff thumb - that is, one that is fairly rigid and inflexible so the tip will not bend backward, to any noticeable degree, indicates that the person is stubborn, has fixed ideas, does not easily adapt to changing circumstances, derives more satisfaction from saving money than from spending it and does not tend to be naturally generous.

Flexible thumb is found when the nail phalange bends back without resistance. It indicates a generous-natured person who enjoys giving or spending and is versatile, adaptable, restless, changeable, tolerant, flexible, interested in many things and willing to listen to new ideas.

Large thumb indicates strength, achievement, capability, self reliance, confidence and inner power. It belongs to a person who can be a leader, a doer. A large thumb adds its strength to other factors in the hand.

Small thumb indicates a weak character -- one who will follow rather than lead. There is little determination or will to win, so this person is easily defeated. A small thumb weakens good qualities elsewhere on the hand.

Medium thumb is the average, neither large nor small, so it endows its owner with the potential to achieve an average degree of success.

Willpower And Reason
The first phalange of the thumb (the one with the nail) relates to willpower and determination; the second phalange relates to reason and logic.

In average hands the second phalange is slightly longer than the nail phalange, indicating normal balance of willpower and reason, found in people who formulate plans and then have the determination to carry them through to a successful conclusion. However, if the second phalange is noticeably longer than the nail phalange, the person thinks about all the things and plans which he intends to put into action but does not have sufficient drive, determination and willpower to translate those ideas into practical reality.

When the nail phalange is longer than the second phalange, the person's reason is overshadowed by willpower, so he or she is the type who acts first and thinks afterwards. This type can be too wilfull and determined for their own good.