Saturday, June 20, 2009

Evolution’s Rainbow

Joan Roughgarden’s Evolution's Rainbow: Diversity, Gender, and Sexuality in Nature and People is a treatise on taking diversity seriously which starts with biology, moves on to biologically-grounded anthropology and concludes with biologically-grounded sociology.

Prof. Roughgarden is not, however, arguing for Sociobiology (or, as it generally known nowadays, evolutionary psychology): or, at least, not as it is generally presented. Evolutionary psychology (and psychology generally) gets a fair bit of stick. She has some particularly harsh comments about psychologists and therapists (p.262), appreciates population geneticist Jerry Coyne’s attack on evolutionary psychology (Pp 173ff) and compiles a list of errors evolutionary psychologists make (p.234). She is particularly not impressed by social scientists who refuse to listen to their subjects (p.382ff):
social scientists who cannot avoid being so judgmental about the subjects they study should find another occupation (p.384).
(Hear, hear: though it would devastate many faculties. Come to think of it, worth it for that alone.)

Her objection to evolutionary psychology is grounded in evidence and is not a blanket rejection—Roughgarden is impressed by evolutionary psychologist Geoffrey Miller’s theory that community interaction selected for higher cognitive capacity (Pp 232ff). Prof. Roughgarden does lapse by suggesting an evolutionary explanation (p.261) for something (the anathematisation of the same-sex active) that, as systematic behaviour, has not been documented in other species: it is specific to a minority of human cultures.
Roughgarden is very much concerned with, indeed celebratory of, individuality. As a transgendered woman, that is hardly surprising. What is more surprising is her critique of individualism. This becomes less so when one realises she is critiquing not individualism per se—there is nothing she has to say in her critique of what she calls ‘individualism’ that would be morally affronting to, for example, the Adam Smith of The Theory of Moral Sentiments—but egoism. That is, a particularly narrow construal of purposes and functions.

The book only contains a brief mention of Malthus (p.161), but I would argue that the use Darwin put Malthus’s population analysis to, encouraged a tendency to see ruthless egoism in natural selection.

This is a very personal book. Prof. Roughgarden connects diversity to her own experience as a transgendered woman (p.2) and ends the book with a short transgender political agenda (p.398) plus an Appendix of policy recommendations.

But is also very much a book concerned with defending and expanding science. She carefully distinguishes factual/biological claims from moral/evaluative ones (p.4). She is against poor science and in favour of good—that is, empirically grounded—science. So biology lapsing at times into derogatory language (p.98) is not only morally offensive, it gets in the way of seeing and understanding what is happening. As the penchant for seeing theft and deceit everywhere blinds biologists to other interpretations of animal behaviour (p.68): her discussion of the biological implausibility of “deceit” and “mimicry” theory (Pp 100ff) is above all a scientific critique.

Part I, Animal Rainbows, takes us through the sexual and gender diversity of nature. It is an excellent and accessible rendition of evolutionary theory, with the caveat that she provides various points against Darwin’s theory of sex selection well before she gets around to explaining said theory in detail.

It is possible to have reproduction in higher animals without sex, as self-cloning, all-female varieties of geckoes prove (p.16). So, why waste all those resources on producing males? By far the most common form of reproduction among animals is males with females. The answer seems to be that diversity is valuable. There is no evidence for the “bad gene” elimination theory of sexual selection (p.20).

Prof. Roughgarden provides a clear discussion of the difference between sex (a biological category) and gender (a social category) (Pp 23ff). The only definition of male and female that does not admit of awkward exceptions is that males produce small gametes (sperm) and females produce large gametes (eggs). Two gamete sizes being near universal: why is not known (p.26).

Prof. Roughgarden defines gender as:
the appearance, behaviour and life history of a sexed body (p.26).
Various species (particularly fish) have more than two genders. Genuine hermaphroditism is rare—female spotted hyenas, who have penises, are not hermaphroditic, they are intersexed (p.38).

Taking diversity to be the empirical reality, rather than an analytical inconvenience, is the basis for an enlightening discussion of reproduction and mating. Prof. Roughgarden examines parental investment levels in reproduction (p.44) and how relative investment affects supply and demand for each sex (p.46)—i.e. who chases whom. She distinguishes economic monogamy (raising offspring together) from reproductive monogamy (only mating together). Monogamy emerges when building opposite-sex relationship is more advantageous to males than building same-sex connections and more advantageous to the female than going alone or with other females (Pp 56ff).

A key point in understanding animal interactions is the need to consider care of offspring—reproductive fitness is not merely producing offspring, but producing offspring who themselves produce offspring (Pp 106ff). Hence the need for cooperation, hence the potential importance of relationships both between and within sexes. Prof. Roughgarden produces a nice list of what sex does—facilitate sharing, aid reconciliation, help integration, build coalitions, be a basis for exchange. And it is also used for reproduction (Pp 149-50).

mating is then more about maintaining the between-sex and same-sex relationships needed to provide food and safety for the young than about sperm transfer as such (p.176).
Prof. Roughgarden argues that females choose well-connected males (p.125). Interactions are about buying support when and if it is needed (Pp 120ff). This is very much against Darwin’s sex selection theory, which defines the purpose of mating as being to exchange semen (p.122).

Darwin’s is the first universal theory of gender in biology (p.164). Darwin was working from limited information and setting aside awkward cases, such as the hermaphrodite barnacles he studied in detail (Pp 166ff). Prof. Roughgarden lists 10 grounds that falsify sex selection theory as template (Pp 165ff). She uses empirical evidence to demolish the “sex selection” theory of rape (Pp 173ff).

The broader analysis is embedded in extensive discussion of the empirical evidence. From the specific—all male garter snakes engage in same-sex copulation every Spring (Pp 96ff)—to the general: why there are species where females look like males (Pp 112ff).

Prof. Roughgarden notes that biologists have been reluctant to acknowledge homosexuality in nature (p.128). But lots of animals engage in same-sex activity: too many to be merely aberrant (p.136ff). It is not mere substitution—for example, same-sex oriented sheep really prefer male sheep sex partners (p.140).

Primate homosexuality is so “in your face” that it is extensively documented back to the 1970s (p.144). But, as Prof. Roughgarden points out, while non-breeding is an evolutionary problem, same-sex sexual activity per se is not (p.156).

Prof. Roughgarden is very much in favour of taking animals seriously—that is, taking what they choose to do seriously. So she is against presenting motherhood as punishment for sex rather than desirable in itself (p.172). She particularly wants to biologists to take cooperation between animals seriously. Nature is pervaded by cooperation as well as competition. Biologist Lyn Margolis established in the 1970s that all plants and animals above the level of bacteria are partnerships at the cellular level (p. 162). Prof. Roughgarden notes that social inclusion mechanisms would help species differentiation (p.180)

Biologically-grounded anthropology
The second Part, Human Rainbows, examines the biology of human diversity. Prof. Roughgarden starts with an “embryonic narrative”—how a person (specifically her) begins from the point of few of egg then sperm then embryo to birth. Then she moves onto the biology of determining sex, with all its interesting diversities—such as ovotestes among females in some species (p.202).

Followed by the biology of sex differences. Prof. Roughgarden argues against assuming uniformity as “the” mode and for facing the reality of diversity between and within groups (Pp 207ff). She explains how the XY system of sex determination is fully compatible with transgender bodies (Pp 214ff). That hormones need the right receptors leads to varied reactions to hormone treatment (Pp 216ff).

Then the biology of gender followed by that of sexual orientation. Prof. Roughgarden argues that sexual orientation is too complex a behaviour to be genetically determined. Which seems entirely reasonable: genes are a recipe, not a mould.

Her discussion of the very limited evidence for genetic influences on sexual orientation (pp 246ff) has a major flaw, however, in that congenital effects that are not genetic are not considered. That something is congenital does not mean that it is genetic: genes are a recipe, not a mould. For example, do twins have exactly the same experience in utero? Does it follow that they would?

Prof. Roughgarden notes that the simple binary model for the brain is breaking down (pp 239ff). The presumptive hostility to variation is further critiqued (Pp 233 et al). One can see that biology has suffered from the male perspective being taken as authoritative, as the template. Darwin may have included female choice, but it was still females responding to males and largely on male terms.

Biology having problems with homosexuality is clearly, in biological theory terms, because sex was about exchanging semen for mating and homosexuality + monogamy = will not breed. But, of course, monogamy does not follow as actual behaviour. Prof. Roughgarden notes that we have insufficient data to show that same-sex attraction in humans is reproductively deleterious (p.258).

On patterns of sexual orientation, Prof. Roughgarden argues that the degree of sexual flexibility itself varies (pp 256ff), which makes sense. (That is, some folk have shifting orientation, others constant; some have narrow sexual interest, others wider, etc.)

She cites evidence that homosexual behaviour is more common in bigger social groups and agrarians than hunter-gatherers (p.260). I hope the study controlled for group size, given that agrarians live in bigger groups than hunter-gatherers.

Prof. Roughgarden provides a useful discussion of what constitutes a genetic disease or defect and the mathematics thereof (Pp 280ff). Taking a 5 out of 100 figure, same-sex attraction is way too common to be a genetic disease or defect (p.284).

Even at 1 in a 1000, transgender identity is also way too common to be a genetic disease or defect (p.286).

So, just as well the American Psychiatric Association took homosexuality off list of diseases in 1973 and the American Psychoanalytic Association rejected reparative therapy in 1998 (p.294).

Engaging empirical data frames her discussion. We discover that, in an area in the Dominican Republic, children born intersex were left in a “gender holding pattern” until they decided their gender identity (Pp 241-2). Prof. Roughgarden can also display a nice eye for irony—Nazi genetic purification strategy, if carried through, would have put the “Aryan” population at considerably greater risk by attacking genetic diversity (pp 306-7).

Biologically-grounded sociology
The third Part, Social Rainbows, builds on the biology (and anthropology) to look at the sociology of human diversity. Particularly gender diversity.

Gender re-assignment surgery has history taking back centuries: indeed millennia. Such as the nirvan ceremony performed by hijra of India (p.346). That what has often be classed as castration may have been deliberate gender re-assignment is enlightening. The transgender perspective informs her discussion of variations in eunuchs in classical antiquity (p.352).

The transgender perspective on Jeanne d’Arc choosing—within the limits of her society—a male gender identity is similarly enlightening (pp 366ff). I liked her discussion of how Greek perspectives on proper same-sex activity enforced their concept of gender differences (p.369).

Prof. Roughgarden sets out just how much gender =/= sexuality. Gender and sexuality are not chosen. They are expressed (though what is being expressed may change).

Obviously much of this goes against traditional religious perspectives. In her discussion of Leviticus and St Paul, she reads them “down” (pp 369ff) so as to reduce the difficulties. Charming idea, but, alas, the wider context suggest her strategy here does not work. Monotheism really does have an endemic problem with same-sex activity.

Prof. Roughgarden discusses violence against transgenders (Pp 388ff) and argues that excluding transgenders makes gay rights more “special” rights than human rights (p.391). On the “alphabet scrabble” issue, she holds that GLBTI (gay lesbian bisexual transgender intersex) is as far as is needed to go (p.392).

The biological reality of transgender humans is that they have always existed, though we may never fully know why (Pp 394ff).

I found Evolution’s Rainbow to be a profoundly enlightening book. Both on biology and evolutionary theory in general and transgender issues in particular. It is also highly readable. It does not merely inform, it educates.

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