  Each of methodological, psychological, and analytical behaviorism has historical foundations. Analytical behaviorism traces its historical roots to the philosophical movement known as Logical Positivism (see Smith 1986). Logical positivism proposes that the meaning of statements used in science must be understood in terms of experimental conditions or observations that verify their truth. This positivist doctrine is known as “verificationism.” In psychology, verificationism underpins or grounds analytical behaviorism, namely, the claim that mental concepts refer to behavioral tendencies and so must be translated into behavioral terms.