Apple CEO Steve Jobs' handwriting betrays some well-known truths about the man, according to graphologist, Shelia Kurtz.

Kurtz is a professional graphologist with 200 corporate clients, and while she agrees handwriting analysis isn't an exact science she is paid up to $400 a time to analyse employee handwriting. Forbes asked her to analyse the signatures of Bill Gates - and Steve Jobs.

Unusually, Jobs does not capitalize the first letters of his name, she noted. She's not sure why, "could it be low self-esteem? Maybe. Could it be that he doesn't let his ego interfere with his understanding? Perhaps."

His handwriting also displays signs of "serious impatience" and a "tendency toward sarcasm", she said.