sentences:  The PCL was originally developed in the 1970s by Canadian psychologist Robert D. Hare for use in psychology experiments, based partly on Hare's work with male offenders and forensic inmates in Vancouver, and partly on an influential clinical profile by American psychiatrist Hervey M. Cleckley first published in 1941.An individual's score may have important consequences for their future, and because the potential for harm if the test is used or administered incorrectly is considerable, Hare argues that the test should be considered valid only if administered by a suitably qualified and experienced clinician under scientifically controlled and licensed, standardized conditions.Hare receives royalties on licensed use of the test.