Chapter 2. The evolution and the rise of human language
Is it the case that a complete psyche discontinuity exists between ape and man, as a function of human consciousness and human grammatical abilities? The genetic evidence makes this seem unlikely. We offer an alternative explanation, based on the plasticity of neuronal development and the discontinuity between infant clinging and infant carriage in ape and human. Human infants not only fail to cling, they display innate motor patterns of rotational hand-waving and leg kicking. These patterns (absent in ape infants) prevent clinging. In their place, ape infants display an elaboration of the moro-reflex, which enables them to cling with all four limbs shortly after birth. The absence of clinging in the human infant is not due to loss of hair, but to the presence of motor patterns incompatible with clinging. The neuronal- developmental consequences of these contrasting innate patterns form the substrate for the emergence of human/ape differences.