Such people have no control over themselves and under the least opposition will fly into a blind rage of fury.

This curious formation has been called the "Murderer's Thumb" because so many who have committed murder in a mad fit of passion have been found with this curious formation.
An employee with this class of thumb should never be given any position of authority over others, for he could not curb his ungovernable temper.
He would also be absolutely unbalanced in his jealousy, and no woman who has the ambition to live to the usual "threescore-years-and-ten" should risk marriage to a man with one of these thumbs.

But as "love is blind" it is useless, I know, to give advice in such a case.
The first joint or nail phalange of the thumb, when long and thin, denotes the opposite of the above characteristics.

In such cases the person has the most absolute control over his temper, his will power is also strong but quick and unobtrusive, and in a firm, determined way people with such a thumb manage others and bend those around them to their purpose.
The second joint, if delicately shaped, almost "waist like," indicates tact, diplomacy, and gentleness, also subtlety in argument; but if this part of the thumb be full looking or equal in size to that of the nail phalange, it denotes the person who cares nothing for tact but who, on all occasions, will speak his mind plainly, and with brutal frankness.
When the thumb looks as if it were "tied in" close to the hand, the person is timid, easily frightened by both people and circumstances, narrow-minded in his views, and miserly in his habits.

It is a well-established fact that the thumbs of all misers are "tied in" and cramped-looking.