摘要：The study of verbal behavior focuses on communicative functions of the speakers/producers as they affect the behavior of listeners/observers. Effects on the listener reinforce the speaker and the listener/observer benefits (i.e., is reinforced) from the behavior of the speaker/producer. The interlocking of, and exchange of, the speaker and listener behavior between individuals and within one’s own skin constitute bidirectional operants. These bidirectional operants are instances of social interactions and measures of social behavior. Evidence suggests that the act of listening, among other observing responses, is initially developmentally independent from speaker behavior. How they become joined parallels the biological phenomenon of metamorphosis. The succession of changes has been empirically identified as a succession of verbal behavior development cusps, which are described in their sequence biologically as a manifestation of functional metamorphosis. The onset of a cusp constitutes first instances of behavior and accompanying stimulus control that allows infants and children to contact parts of the environment for the first time resulting in their learning things impossible to learn before or learning faster. Cusps for the intercept of the speaker and listener lead to bidirectional operants and provide explanations for how children incidentally learn the names of things, become increasingly social, and make subsequent complex behavior possible. Many of the cusps identified in our research resulted from the missing behavior and stimulus control of children with autism. Once cusps were established, these children learned things they could not learn before, learned faster, and learned by contacting parts of the social environment they could not contact before. These findings led to a theory of verbal behavior development that point to the selection of bidirectional operants as behavioral phenotypes during functional metamorphosis, which has enhanced the survival of Homo sapiens through emergent symbolic skills for more effective collaboration between two or more individuals.
