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.
"At about noon the first heavy drops of rain began to fall. The chimpanzees climbed out of the tree and one after the other plodded up the steep grassy slope toward the open ridge at the top. There were seven adult males in the group, including Goliath and David Greybeard, several females, and a few youngsters. As they reached the ridge the chimpanzees paused. At that moment the storm broke. The rain was torrential, and the sudden clap of thunder, right overhead, made me jump. As it this were a signal, one of the bid males stood upright and as he swayed and swaggered rhythmically from foot to foot I could just hear the rising crescendo of his pant-hoots above the beating of the rain. Then he charged off, flat-out down the slope toward the trees he had just left. He ran some thirty yards, and then, swinging round the trunk of a small tree to break his headlong rush, leaped into the low branches and sat motionless.
Almost at once two other males charged after him. One broke off a low branch from a tree as he ran and brandished it in the air before hurling it ahead of him. The other, as he reached the end of his run, stood upright and rhythmically swayed the branches of a tree back and forth before seizing a huge branch and dragging it farther down the slope. A fourth male, as he too charged, leaped into a tree and, almost without breaking his speed, tore off a large branch, leaped with it to the ground, and continued down the slope. As the last two males called and charged down, so the one who had started the whole performance climbed from his tree and began plodding up the slope again. The others, who had also climbed into trees near the bottom of the slope, followed suit. When they reached the ridge, they started charging down all over again, one after the other, with equal vigor.
The females and youngsters had climbed into trees near the top of the rise as soon as the displays had begun, and there they remained watching throughout the whole performance. As the males charged down and plodded back up, so the rain fell harder, jagged forks or brilliant flares of lightening lit the leaden sky, and the crashing of the thunder seemed to shake the very mountains.....Twenty minutes from the start of the performance the last of the males plodded back up the slope for the last time." (Goodall, Jane (1988) In The Shadow of Man. Houghlin Mifflin: Boston p. 52-53)
"In other words, chimpanzees are very promiscuous, but this does not mean that every female will accept every male who courts her." (Goodall, Jane (1988) In the Shadow of Man. Houghlin Mifflin: Boston pp. 187-8)