This paper points out the inadequacies of emotional or drive-based theories of exploratory behavior and offers instead a behavior analysis conceptualization. Exploratory behavior as an emotional state was rejected because the environmental conditions said to arouse exploration and the behaviors said to manifest curiosity are too general to separate from other kinds of interactions. The drive theory was discarded for two reasons: (1) physiochemical change as the distinction between exploratory and non-exploratory behavior has not yet been clearly demonstrated and (2) the collative stimulus approach, in which the comparison of stimuli is said to arouse curiosity and thus lead to specific exploratory behavior, has not facilitated research. Behavior analysts contend simiply that exploratory behavior generates repertories that facilitate the development of complex cognitive behavior and is the sort of behavior that is established and maintained by nonappetitive reinforcers. (JMB)