A chip on one's shoulder

            A Chip on my Shoulder

It is interesting to know how the phrase “A chip on my one’s shoulder” originated.  People tend to use the phrase to indicate that one may have a grudge against another.  It seems to have originated two centuries ago.  It tends to indicate that there once was a physical meaning where one person would dare another, in a dispute, to knock a chip which was placed on his shoulder, off. 

Lately, in the last few decades the phrase “a chip on one’s shoulder” seems to mean a sense of superiority.  The young man walks around the office with a chip on his should because his father owns the business.