Human evolution theory utilizing concepts of neoteny & female sexual selection
An etiology of neuropsychological disorders such as autism and dyslexia, and the origin of left handedness.
"As early as the first day of life, the human neonate moves in precise and sustained segments of movement that are synchronous with the articulated structure of adult speech. These observations suggest a view of development of the infant as a participant at the outset in multiple forms of interactional organization, rather than as an isolate. ... In contrast, microanalysis of pathological behavior -- for instance, that of subjects with aphaic, autistic, and schizophrenic conditions -- reveals marked self-asychronies. Delayed auditory feedback also markedly disturbs this self-sychrony. ... For example, as the adult emits the KK of "come," which lasts for 0.07 second, the infant's head moves right very slightly (Rvs), the left elbow extends slightly (Es), the right shoulder rotates outward slightly (ROs) the right hip rotates outward fast (ROf), the left hip extends slightly (Es), and the big toe of the left foot abducts (AD). These body parts sustain these directions and speeds of movement together for this 0.07-second interval. This forms a "unit" composed of the sustained relation of these movements of the body. ... This 2-day-old infant displayed segments of movement synchronous with the adult's speech during the entire 89-word sequence. In other words, this is a sustained and precise occurrence. Another 2-day-old infant sustained similarly synchronous movement throughout a series of 125 words of tape-recorded female speech. ... This study reveals a complex interaction system in which the organization of the neonate's motor behavior in entrained by and synchronized with the organized speech behavior of adults in his environment. If the infant, from the beginning, moves in precise, shared rhythm with the organization of the speech structure of his culture, then he participates developmentally through complex, sociobiological entrainment processes in millions of repetitions of linguistic forms long before he later uses them in speaking and communicating. By the time he begins to speak, he may have already laid down within himself the form and structure of the language system of his culture. This would encompass as multiplicity of interlocking aspects: rhythmic and syntactic "hierarchies," suprasegmental features, and paralinguistic nuances, not to mention body motion styles and rhythms. This may provide an empirical basis for a new approach to language acquisition." (Condon, W.S. & Sander, L.W. (1974) Neonate movement is synchronized with adult speech: interactional participation and language acquisition. Science 183: pp. 99-101)