ABSTRACT
At this point in the argument a testing of the main hypothesis can be made. The main hypothesis is that the experience of the proto-conversation is the origin of the activity of pretend play and the ‘doubling’ of symbolic thought. The hypothesis predicts that impediments to the establishment of the proto-conversation will lead to the developing child having deficiencies in both areas. Children who are born blind and deaf, whose participation in one sensory modality of the proto-conversation is blocked, show such deficiencies.
