Jealousy and Self-Esteem:
"Jealousy and Envy (quick dictionary definition): painful desire of another's advantages. Jealousy is about losing a value to someone else (the context for jealousy is always social). It is a painful feeling regarding a value one has and is afraid of losing - or something a person has difficulty having, but see another enjoying. Example: Seeing the object of your romantic interest showing affection to someone else. Envy is about something one does not have, does not believe he can have,and yet see another person having and enjoying. "

A very interesting article from an interesting artist who happens to be a Bio-Medical Engineer.