What is a Felon's Claw?

A felon's claw is a feature in graphology, the study of handwriting. The tails of small letters like p,q,f,g and y which go below the base line are thought by some to reveal aspects of a person's basest feelings, what psychoanalysts call the id.

If the tail of a g or y, instead of continuing in a smooth curve, stops and arches backwards, it is said to indicate a rebellious phase in a young person.If it continues into adulthood, this is said to be a common trait of criminals.The following Youtube video describes this, and also the related Madonna syndrome:
https://m.youtube.com/watch?v=tsO8m_Rdqsc

If you are in a rush, you might like to jump to the 4:15 mark in the video.