There have been studies conducted that note the testosterone levels in males at different levels of a primate hierarchy.  Conclusions correlated hierarchical positions with testosterone levels.  Higher thresholds congregate at higher hierarchical positions, lower thresholds at lower positions.

I don’t know of studies conducted that match up testosterone levels with maturation speed, delayed maturation being associated with lower testosterone levels.  Bouncing around the web, I find that there are sites that suggest it.  For example, males denied testosterone mature more slowly and live several years longer.

What interests me at this moment are studies that would observe changes in estrogen being accompanied by changes in mate-selective intensity.  Perhaps this would be easier to observe in humans.  With certain fish, male tails were artificially elongated, with the females becoming attracted to those longer-tailed fish.  What if the amount of estrogen or estrogen-related hormones were modified to increase or decrease with the female?  Would she show more or less compulsion to exercise choice?  Would she become more discriminating with higher estrogen?

Estrogen seems associated with at least two powerful female features, attention to the young and attraction to nuance.  They seem related in that attention to the young often revolves around attention to detail.  Perhaps the attention to the aesthetic details characteristic of sexual selection has its origins in focus on the young.  That would suggest that those species with females most engaged in sexual selection would be species where the young are nurtured for at least some time, or their evolutionary forebears were engaged in that process.

I mentioned this to Paul, and Paul suggested some females spend no small amount of time picking just the right place to place their eggs.  Might that pickiness be related to estrogen?  When the males do the nest searching, are those males exhibiting higher estrogen levels?

Nevertheless, with females having higher levels of estrogen than males, and females often engaged in sexual selection and feeling attracted to the young, one would expect variations in those behaviors with variations in the levels of estrogen or estrogen-related hormones in their systems.

It’s always a little weird when I conduct a search in Google for a correlation that seems pretty obvious to me, for example “estrogen” and “sexual selection,” and find my sites coming up in the top of the searches.  Ten years ago, I posted  There I discussed in detail the connection between testosterone and autism.  Conducting searches, I found that my sites came up first with no discussion of the connection on other sites.  Now, it’s a conventional connection what with the astonishing work of Simon Baron-Cohen and his colleagues.

I have been considering that testosterone, estrogen and autism are all related. (Click here).  A premise in that conjecture is that as estrogen levels change, so do compulsions to sexually select, with humans selecting for neotenous or childlike features.  This seems pretty basic to me.  I need to explore what the literature is on the subject.


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