“The diversity of human skills and the improbability that any one individual could be good at everything makes it reasonable to suggest that different genotypes, for different patterns of CD [cerebral dominance], are associated with various strengths and weaknesses that complement and balance one another in the population as a whole.” (Annett, Handedness and Brain Asymmetry, p. 186)

Thirty years ago in Guatemala, a student of Marian Annett, W. J. Demarest, evaluated Mayan and Ladino (mixed Spanish and Indian) children to see if their handedness distributions were similar to Annett’s UK studies.  Annett hypothesized that the way that the British are cerebrally organized would carry over to humans across the planet based upon the fairly consistent manifestations of left-handedness that are observed.

The conclusion of the Guatemalan study suggested that the Mayan children did not exhibit the same distribution of handedness, implying a different distribution of cerebral lateralization.  The Mayan children drifted further to the left, emphasizing that they might be less lateralized for language.  The thesis of this website would argue that the Mayans exhibit a more matrifocal social structure than Western societies, the left drift in handedness appraisals suggesting an older genotype.

In another study, indigenous Americans located in the Amazon rain forest were described as being more right-handed than the European norm.  The Yanomano of the Amazon are violently patrifocal with ratios as high as 140/100 male/female, with female infanticide being the convention.

If we assume that South and Central American indigenous populations migrated from Asia at about the same time, and that varying handedness distributions across the Americas reflect social structure, then it would be interesting to consider that as social structures metamorphosized over time, those changes were accompanied by degrees of handedness.

If a society over the course of thousands of years moves back and forth, left and right across the cerebral dominance/handedness/social structure distribution, informed by a mother’s uterine testosterone and estrogen levels, do changes in the mother’s hormone levels delaying rates of maturation for males, accelerating them for females, sometimes result in a reverse effect?

For example, let’s make believe that the Mayans were Yanomano-like 3,000 years ago, engaging in female infanticide, warrior-like, combative to a T.  If a contemporary Mayan baby were compelled to evolutionarily drift backward by changes in a mother’s uterine testosterone levels, and the child drifted back 3,000 years to when male testosterone levels were high, not low, what would be the maturation rate and testosterone level of the children?

If we assume that we were matrifocal as we departed Africa 50,000-80,000 years ago, growing more patrifocal over the millennia, what of those that grew patrifocal, and then drifted back in a matrifocal direction?  In other postings, I’ve proposed that is exactly what is occurring now in the U.S., led by what is happening in Scandinavian countries.  Consider that in Scandinavia, possibly highly patrifocal in the relatively recent past, embryos now bathed in a high-testosterone uterine environment propelling them into the past might arrive instead in a patrifocal society.

Unless Scandinavian contemporary matrifocal society is already firmly established further past or back than the evidence of their relatively recent patrifocal frames.

That would suggest that the hypothetical Mayans with a Yanomano past are hormonally the ancestors or forebears of the Yanomano.

I guess I’ve answered my question, untied the knot.  The implication is that there are smaller waves within the larger waves of our evolution where past and future are extremely relative.  What would seem to be an innovation may be an ancient re-emergence.  What may seem like moving forward in time is moving back.

Contemporary piercings, tattoos, rhythmic music, far less marriage than in the recent past may all be profoundly non-innovative.  Many contemporary trends may be examples of our changing cerebral dominance, handedness, social structure proclivity and hormonal constellations as we drift backward in hormonal time.


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