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.
"There are three societies, accounting for 28 of the populations, which are coded in the Ethnographic Atlas as patrilocal or virilocal (the Yanomamo account for 26 populations). The average sex ratio in the junior age grade for these populations is 142 males per 100 females. Seven of the societies are coded in the Atlas as uxorilocal or neolocal, and the remaining case, the Guana, appear not to be patrilocal. These eight societies account for 20 populations with an average junior sex ratio of 103 males per 100 females. Thus while the warring societies as a whole have an average junior sex ratio of 126:100 it is the patrilocal component of the sample which produces the bias while the nonpatrilocal component shows a nearly even sex ratio. This correlation suggests that there are different cost/benefit ratios for raising daughters, given different residence arrangements. For this sample at least, nonpatrilocal systems do not support female infanticide. ... Divale (1974b) has shown a correlation between external warfare (in the absence of internal war) and matrilocality, and Harris has elsewhere emphasized this correlation (1977), noting also an association between matrilocal residence and a "diminution in preferential female infanticide" (1977:63). " (Hawkes, Kristen (1981) A third explanation for female infanticide. Human Ecology 9,1: pp. 83)