Rudeness is the compensating tool used by the completely inadequate man so he feels good about himself, while hurting others.

From your definition, it can be deduced that, people who exhibit rudeness might be suffering from low self-esteem. However, that is just a null hypothesis. As such, I might take interest to carry out a research on this.

• How likely are people with low self-esteem to become rude?
• Is there a correlation between low self-esteem and rudeness?
• If there's any, is the correlation a strong one or weak one?

Well done @ejemai, you've given me something to ponder on.