According to Deep Research of Guruji Dr Praveen Kochar Ji as a Palmist ,Thumbs are either firm or flexible. If it bends backwards from the joint it is regarded as being flexible . Someone with this characteristic will be easy-going, positive, and flexible. He or she will also give in under pressure, rather than create a scene. the thumb is stiff and does not bend back at the joint it is classified as being firm. Someone with this type of thumb will be determined, reliable, and stubborn. He or she will be unyielding and not give in under pressure.