The zone of proximal development (ZPD) is defined as an overarching concept that integrates the main tenets of Vygotsky's theory of human development. The conceptualization of the ZPD begins with its social, cultural, and historical context and traces its development as a spatial and temporal metaphor that reflects the sociogenetic root of all…

The placement of laughter in the speech of hearing individuals is not random but "punctuates" speech, occurring during pauses and at phrase boundaries where punctuation would be placed in a transcript of a conversation. For speakers, language is dominant in the competition for the vocal tract since laughter seldom interrupts spoken phrases. For…