Machiavellianism is primarily the term some social and personality psychologists use to describe a person's tendency to deceive and manipulate others for personal gain. The concept is named after Renaissance diplomat and writer Niccolò Machiavelli, who wrote Il Principe (The Prince). (Machiavellianism can also refer to the doctrine Machiavelli established, although that is not the subject of this article.) In the 1960s Richard Christie and Florence L. Geis developed a test for measuring a person's level of Machiavellianism. This eventually became the MACH-IV test, a twenty-statement personality survey that is now the standard self-assessment tool of Machiavellianism. People scoring above 60 out of 100 on the MACH-IV are considered high Machs; that is, they endorsed statements such as, "Never tell anyone the real reason you did something unless it is useful to do so," (No. 1) but not ones like, "Most people are basically good and kind" (No. 4). People scoring below 60 out of 100 on the MACH-IV are considered low Machs; they tend to believe, "There is no excuse for lying to someone else," (No. 7) and, "Most people who get ahead in the world lead clean, moral lives" (No. 11). In a series of studies undertaken by Christie and Geis and Geis's graduate assistant David Berger, the notion of machiavellianism was experimentally verified.