Real Dictionary

behaviorism
uncountable noun: Behaviorism is the belief held by some psychologists that the only valid method of studying the psychology of people or animals is to observe how they behave.

behaviorism in American English
the doctrine that observed behavior provides the only valid data of psychology: it rejects the concept of mind and consciousness
noun: the theory or doctrine that human or animal psychology can be accurately studied only through the examination and analysis of objectively observable and quantifiable behavioral events, in contrast with subjective mental states