Gender and sexuality as continuums rather than two-sided coins in Jared Diamond’s ‘The Third Chimpanzee’

Like many of our PopMythology fans, I’m sure, I’ve been enjoying Neil deGrasse Tyson’s revival of Cosmos.  I am actually old enough to have watched the original series, and it certainly played a part in my decision to become a lab geek.  But more than just inspiring young scientists, these types of popular media have a more important role of communicating basic science to everyone.  Why is this important?  Well, because the more one learns, the more open one’s mind becomes, because half of learning and knowledge is to discover the extent of your own ignorance.  So my hat’s off to all those engaged in those engaged in television, movies, writing, lecturing, and all sorts of methods to bring a little understanding in an interesting way to everyone.

Episode 2 of Cosmos dealt with the always controversial subject of evolution.  I thought the show provided a wonderful and very accessible overview of the subject, but at the end of the show my husband, who is not a scientist, was ready to hear more.  Being ever the bookworm, my answer was, to him and anyone else who might feel the same way, read Jared Diamond’s The Third Chimpanzee.

Jared Diamond, like Bill Bryson whom we’ve reviewed here  in the past, is one of those gifted non-fiction writers that can explain anything to anybody, and make it interesting.  To encourage you to read the book, I want to cover one small topic in the book and show how science knowledge can open minds and help change the world. The particular example is a discussion about sex chromosomes, what they do and don’t do, and how this science could potentially contribute to the discussions of gender and all things sociologically related to it.

The book launches into the discussion from the larger consideration of child-rearing roles, which have traditionally been the domain of women. Often a biological argument is made to reinforce these roles, particularly citing the inability of men to breast-feed. Diamond, however, points out that, believe it or not, lactation is within the physiological potential of males, given the appropriate hormonal injections which are sometimes necessary for women also. This is staggering to consider- the concept that post-partum, with minor medical intervention, male versus female care could be completely equivalent. Now I’m not necessarily advocating for male breastfeeding as standard practice, but it does beg the question of what exactly are the differences between genders.

As is turns out, not very much actually, at the gene level. Most of us recall from our high school biology that in humans the twenty-third chromosome is matched in women (as XX), but mismatched in men (as XY). This Y chromosome is the sole difference and one can hear this difference invoked multiple times daily to explain an infinitely wide range of behaviors (**insert your favorite sexist joke or cliché here**) for both men and women. But the truth is that the Y chromosome is much smaller than all the others and only contains a handful of genes on it. Functionally what the Y chromosome does is instruct a gonad in about the seventh week of embryonic development to become a testis. Without these instructions, the gonad will become an ovary. That’s it, for the most part. From there, secretions from the testes (e.g. dihydrotestosterone) channel other bifunctional structures into male organs which, in the absence of such secretions, become female organs. The levels of these secretions can vary widely in individuals and may in extreme cases produce instance of hermaphroditism, such as the case explored in Jeffery Eugenides novel Middlesex.

The key thing to understand is that the sexual organs are potentially bifunctional initially and are only developed after the initial formation of the testes by this gene on the Y chromosome, and from there it is a matter of hormones and degrees. The female steroid hormones, estrogens, are actually present to varying degrees in men, and women have differing levels of testosterone as well. Steroid hormones can affect behavior, and as a statistical average the male population does have higher levels androgens and the female higher levels of estrogens. Among humans, though, there is wide and overlapping spectrum of values, and these levels also vary throughout and individual’s lifetime.

Given this, one might potentially have a biological framework for viewing gender in society as something much more complex than two sides of a coin, but rather a whole wonderful continuum of possibilities. We might be able to quit talking endlessly about what men want and women need and instead focus on human desires and requirements, or, even better, individuals. And what’s more, under this paradigm, the whole matter of sexual orientation becomes all but nonsensical and irrelevant. Too bad John Lennon’s not still around to write us another verse of “Imagine”.

So consider this a shout-out to Tyson, Diamond, and all the science educators out there. Rock on, folks.