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.
"Studies indicated that musicians differ from nonmusicians in functional hemispheric lateralization (Gordon, 1983; Hassler & Birbaumer, 1988; Witelson, 1980) in that musicians are less left-lateralized than nonmusicians for language functions." (Hassler & Birbaumer, 1988) at each stage of the study." (Hassler, M & Nieschlag, E. (1991) Salivary testosterone and creative musical behavior in adolescent males and females. Developmental Neuropsychology 7: 518)
"It seems possible that an optimal testosterone range exists for the expression of creative musical behavior and that exceeding this optimal range in the course of puberty may contribute to a stop of musical production in boys. Such optimal testosterone levels may be lower than male average in adult men and higher than female average in adult women (Hassler, 1991; Hassler & Nieschlag, 1989). ... Handedness proved to be an important variable with respect to musical talent in boys. Male left-handers attained significantly higher mean test scores than male right-handers on Wing's Standardized Tests of Musical Intelligence (Hassler & Birbaumer, 1988) at each stage of the study." (Hassler, M & Nieschlag, E. (1991) Salivary testosterone and creative musical behavior in adolescent males and females. Developmental Neuropsychology 7: 504)