Verbal Milestones: Joining of Listener and Speaker Responses Metamorphosis Status: Butterfly
Self-Talk conversational units in fantasy play (speaker as own listener within the skin made overt)	New Learning Possibilities: Self-talk is a key developmental stage, from both the verbal behavior and cognitive and developmental psychology perspectives. Self-talk may be a prerequisite to other bidirectional operants such as BiN [3] . Skinner [1] proposed that self-talk spoken aloud is a precursor to covert behavior as Lodhi and Greer [68] demonstrated. As children acquire audience control, the behaviors move from overt to covert. Young children often emit self-talk conversational units during pretend play.
Conversational Units	A verbal episode in which both parties function s a speaker and a listener in one single episode [99] Skinner’s [1] verbal episodes Advanced intraverbal responding	Social Listener Reinforcement Protocol [68] [99] [100] [101] [102]
	New learning opportunities: Children who emit conversational units are reinforced as a listener and speaker. Children who do not emit conversational units may respond to intraverbals initiated by a peer or adult (sequelics), or will emit mands, but will not initiate intraverbals or may not emit tacts to peers. When children emit conversational units, they have reinforcement for listening to a peer or adult, and ask questions so that they can listen. Thus, procedures to induce conversational units must teach reinforcement for listening and create the correct establishing operations for listening [3] [100] [101] [102] [103] . Conversational units are hallmarks and a primary measure of social behavior. Conversational units include spoken and non-spoken verbal exchanges. Many of the important social components are non-vocal but verbal.
Say-Do Correspondence	A verbal behavior cusp that enables one to function as a listener to their own verbal behavior and follow the directions given to him/herself.	Correspondence between saying and doing protocol [67] [103]
	New learning opportunities: Say-do correspondence is the beginning of the rotation of listener and speaker roles within one’s skin. Conversational units typically demonstrate say and do correspondence.
Audience Control	A verbal behavior cusp that leads one to engage in different verbal responses in the presence of different audiences.	Social Listener Reinforcement Protocol [1] [3] [100] [101]
	New learning opportunities: Children with audience control emit certain behaviors and verbal responses in the presence of peers that differ from responses that when they are alone or in the presence of adults. Behavior changes in ways that are sensitive to the reinforcing and punishing contingencies of a given audience, hence social awareness.
BiN Accrues from Listening to a Story Read by Others or Reading	A cusp that allows one to acquire incidentally the name of a stimulus through listening to a story or reading such that they can emit the name in the speaker or listener functions without direct instruction.	Word-picture matching discrimination [51]
	New Learning Opportunities: Children learn names of educational stimuli through listening to a teacher read aloud.
Conditioned Reinforcement for Observing Books	An individual who has conditioned reinforcement for observing books will choose to look at books during leisure time. This cusp includes behaviors such as turning pages, looking at pictures, and emitting tacts. It is an empirical test of “reading readiness.”	Stimulus-Stimulus Pairing Protocol [74] [104] [105] [106] [107] [108]
	New learning opportunities: Accelerates learning to textually respond and comprehend. This is a foundational cusp for textual responding (see and say) and textual responding with comprehension. The child can be introduced to phonetic reading instruction, expanding their verbal behavior community to print.
Textually Responds at 80 Words per Minute	Individuals emit textual responses under the control of print stimuli. They become fluent readers when they can respond at 80 words per minute, beyond a simple see-say relation.	Fluency Training Protocol [3] [109]
	New learning opportunities: When readers are fluent, they can comprehend what they are reading. However, comprehending what is read is not necessarily an outcome of textual responding. The listener within the skin must be engaged simultaneously in listening to the textual responses. Moreover, Conditioned Seeing appears to be a component [104] [105]