When I was exploring the possibility of a human genetic precursor that was random-handed with a larger brain encouraged by a song-and-dance-based matrifocal culture, I hypothesized that if representatives of our ancestors were around today, they would have larger brains and difficulty with language.

The premise is that the exponential growth in brain size through the history of Homo erectus and before was driven by the selection for mates talented in dance. An established biological pattern is that predators have larger brains than their prey. More demanding physicality (it’s more difficult to be a predator than to run away) creates a requirement for increased neurological support. Dance may have been a sexually selected physical demand with no upward threshold in satisfactory results. Rampant brain growth may have been the result of males competing for the attention of females in matrifocal societies where males that exhibited neotenous characteristics (creative, playful, cooperative) were the most likely males to procreate.

The best dancers had bigger brains. The best way to select for bigger brains over time was to choose males exhibiting neotenous characteristics. Neotenous males are cooperative males supporting a matrifocal social structure.

When I was first monkeying around with these ideas, noting that studies reported that our brains were growing smaller in size about 25,000 years ago, I surmised that an emergence of patrifocal social structure, right-handedness and a smaller brain might be all related. If this was the case, then there might be representatives of language-challenged, bigger-brained people around. I had worked with autistic children. I investigated the literature for evidence of autistic people having bigger brains.

Autistic people have bigger brains.

I then began to explore the literature for evidence of other signs.

Chimpanzees and gorillas exhibit the extremes of the great ape social structure. Chimp males have large testicles to be able to produce the prodigious amounts of sperm required to sire a child. A female in estrous may copulate with several males in a day. Gorillas have small testicles. The male silverback controls the females by physically dominating the other males. He can copulate at his leisure, relatively certain the progeny will be his. Less sperm required. I hypothesized that in a matrifocal social structure, balls would have to be bigger than in a patrifocal set-up. There was some support of this in the literature in contemporary cultures. Highly stratified patrilineal cultures, as a rule, had males with smaller testes than males with more recent matrilineal connections.

The question was: Did bigger-brained males also have larger testicles? Did ambidextrous males, left-handed males or autistic males–hypothesized to be males with an older genotype from matrifocal societies–have bigger balls?

Culling through hundreds of papers, I was unable to find any studies on testicle size as it relates to handedness, autism or conditions characterized by maturational delay. There was one exception. Autistic males with the condition called fragile X had huge testicles. But these autistic males were a genetic anomaly.

Consider that with the exponential increase in autistic children, we are seeing a resurgence of individuals with no communicative impairments that are close genetic relations to people with conditions characterized by extreme maturational delay or autism. Look for unusually articulate, big-brained, big-balled, cooperative, artistic, left-handed dancers. Those would be the guys who are getting all the girls.


This entry was posted on Sunday, July 13th, 2008 at 5:45 am and is filed under 10-Autism, 10-Most Commented, Autism, Autism Features, Biology, lefthanded, Neoteny, Ontogeny, Sexual Selection, Sexual Selection/Social Structure, Society. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.
3 Comments so far

  1. Tommy on July 22, 2008 11:33 pm

    Your site has some interesting thoughts and theories. I came back to it after not having read it for awhile and read this article. It made me laugh and made me think considering things about myself.

    My son is on the Autistic Spectrum and is considered “High Functioning”.

    My wife is a high testosterone female and also a late bloomer. I’m a low testosterone male, 3rd son of a 3 male family born from a father who was the 3rd son of a 3 male family. I’m not left handed, but I’m all the things you talked about. I could get all the girls, I get along with girls best, and I used to be confused for being gay because I never was very masculine. I didn’t hit puberty till 15 and my body never got that “man” shape until around 28 or 29 years old. I was always very slender. I have always enjoyed dancing, listening to music, introspection, discussions, and thinking creatively about whatever it is that I’m currently obsessed about.

    If you have any questions or thoughts, let me know :) I’ll read more of your site when I get a chance.

  2. Charlene Croft on July 31, 2008 8:10 pm

    I was directed here by a comment on my blog and I am glad I clicked… I’ve poked around your ideas and I must say I am very impressed and excited about your writings.

    I am going to have to print much of the text and dive into it, as I have difficulty reading intensely from a screen, and it seems as though I will need undivided attention to digest this.

    Glad to find another brain that recognizes how complex this autism thing is… one that is writing about it as well.

  3. Andrew on July 31, 2008 8:41 pm

    Thank you, Tommy and Charlene.

    As noted in this entry and others in the austism section of the site, several aspects of evolutionary theory converge to reveal the processes behind autism. I’m not sure it’s as complex as it is unfamiliar. Sexual selection and Larmarckian processes have been little explored to explain neurological or physiological anomalies or conditions. Neoteny isn’t the first word most think of when they consider how human beings evolved.

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