Niccolo Machiavelli was an Italian political writer at the time of Renaissance. His book "The Prince" became notorious for its rather amoral outlook, and his name has therefore entered the language to describe people who plot, plan, calculate, double-cross and trust no one but themselves. People who score highly on such a scale usually think of themselves as hard-boiled or realistic. They feel that most people are just too niave to live. Machiavellianism may not be the most attractive personailty trait, but it is widely found among people who wheel and deal for a living. A naive and trusting politician, for example, would not last long. A Machiavellian one might end up as head honcho. See how you measure up on this scale.