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.
"And the beat goes on. When friends are hooked up to electro-encehalographs, which measure brain activity, the resulting tracings show that even brain waves get "in sync" when two people have a harmonious conversation. In fact, if you sit at the dinner table and watch carefully, you can conduct the conversation with your hand as family members talk and eat. Stressed syllables usually keep the beat. But even silences are rhythmic; as one person pats her mouth, another reaches for the salt--right on cue. Rests and syncopations, voices lowered, elbows raised, these mark the pulse of living as well as of love. Our need to keep each other's time reflects a rhythmic mimicry common to many other animals. On a number of occasions primatologist Wolfgang Kohler entered the chimp enclosure in a primate research center to find a group of males and females trotting in "a rough approximate rhythm" around and around a pole. Kohler said the animals wagged their heads as they swung along, each leading with the same foot. Chimps sometimes sway from side to side as they stare into one another's eyes just prior to copulation too. In fact, nothing is more basic to courtship in animals than rhythmic movement. Cats circle. Red deer prance. Howler monkeys court with rhythmic tongue movements. Stickleback fish to a zigzag jig. From bears to beetles, courting couples perform rhythmic rituals to express their amorous intentions. To dance is natural. So I think it reasonable to suggest that body synchrony is a universal stage of the human courting process: as we become attracted to each other, we begin to keep a common beat." (Fisher, H. (1992) Anatomy of Love: The Mysteries of Mating, Marriage, and Why We Stray. Simon & Schuster, New York, 1992. pp. 31)
"A few decade ago Otto Jespersen, the Danish philologist, even speculated that early human courting sounds stimulated the evolution of language. "Language," he said, "was born in the courting days of mankind; the first utterances of speech I fancy to myself like something between the nightly love-lyrics of puss upon the tiles and the melodious love-songs of the nightingale."25 This sounds farfetched. There were probably several reasons why early men and women needed advanced communication. But love songs, like national anthems, can certainly "stir the blood." (Fisher, H. (1992) Anatomy of Love: The Mysteries of Mating, Marriage, and Why We Stray. Simon & Schuster, New York, 1992. pp. 36)