Friday, June 7, 2019

Sex, Sexuality and doing evolutionary reasoning badly

This post by Darwinian Reactionary provides an excellent example of using evolutionary reasoning badly.

He is using evolutionary reasoning to critique the notion of sexual orientation. There are lots of problems with the concept of sexual orientation. Starting with the fact that human sexuality is multi-dimensional. There is (1) who you fall in love with, (2) who you are sexually attracted to and (3) who or what can provide sexual release. The randier you are, the wider (3) is likely to be, and the broader than (1) and (2) it is likely to be.

As lots of homosexual men down the ages have discovered, a significant proportion of straight young men are, in the right circumstances, seducible. That does not make them bisexual or homosexual, it just makes them randy. Men, particularly young men, in situations which systematically deny them social contact with young women are likely to use other men for sexual release. That is true in prisons, on long sea voyages and in countries which practise sexual apartheid.

The concept of sexual orientation does not really cover all those dimensions. It also does not cover terribly well the evidence that female sexuality seems to be moderately more fluid than male sexuality.

Evolutionary complexity
The problem with Darwinian Reactionary's critique is not that it is directed against the concept of sexual orientation, nor in invoking evolutionary reasoning, it is how evolutionary reasoning is used.

The first difficulty is simply assuming homosexuality is an absolute evolutionary disadvantage: in effect, that it completely blocks reproduction. Lots of homosexuals have had children. It is perfectly reasonable to suggest that homosexuality is somewhat of an evolutionary disadvantage in that homosexuality presumably does reduce the propensity to reduce. It is, however, an empirical matter how much it actually does. An empirical matter that, moreover, is likely to vary significantly from human society to human society.

How much a barrier to reproduction homosexuality actually is matters, because it affects how strong the evolutionary pressure is against any genetic basis for homosexuality. The less of a barrier to reproduction homosexuality turns out to actually be, the less evolutionary selection pressure there is against it, and the less a puzzle its persistence in human populations is.

Let us presume, however, that homosexuality is enough of a barrier to successful fertility as to create a significant and persistent element of evolutionary pressure against it. Then we have a puzzle to be answered: why is it persistent? Note that this is not quite the same puzzle as: why does it exist? The latter is a puzzle of identifying the causal mechanism, the former is a puzzle about the persistence of the causal mechanism.

The “gay uncle helps sibling reproduction” hypothesis has some empirical support, though probably not enough in itself to explain the persistence of homosexuality. Especially if we assume homosexuality is an absolute barrier to reproduction, there may be problems with making the evolutionary mathematics work. It would be an informative exercise to work out what level of depressed reproduction above zero is sufficient for the mathematics to work, remembering that the more children the gay uncle tends to have, the less plausible any advantage to sibling reproduction is. Perhaps both effects cancel each other out, but it seems worth checking range and scale.

Cognitive dimorphism
Leaving aside the problem of assuming an absolute selection disadvantage, a further problem with Darwinian Reactionary’s use of evolutionary reasoning is that it is not based in the complexities of being Homo sapiens.

What is missing from the evolutionary reasoning in Darwinian Reactionary’s post is what is often missing from such reasoning: any sense that we are specifically dealing with Homo sapiens. It is all just logic pertaining to a sexually reproducing species. Nothing specific to Homo sapiens is involved.

Three factors specific to Homo sapiens appear relevant: (1) we are the cultural species, (2) we are the non-kin cooperation species and (3) there are significant, at least partly innate, cognitive differences between men and women. (1) and (2) are relevant because homosexual men have a persistent, cross-cultural tendency to be disproportionately involved in cultural activities, (3) because homosexuals have a persistent, cross-cultural tendency to display cognitive traits more common in the other sex. Indeed, their defining characteristic—who they are sexually attracted to—is the most obvious example of this but, revealingly, not the only one.

As an aside, this makes all the more annoying the tendency to reason abut homosexuality and homosexuals in ways which make it blindly obvious that one has entirely failed to consult the experience of actual gay folk. (A tendency much more obvious in the comments on the aforementioned post than the post itself.) One may choose what one does (or does not do) for sexual release. One does not choose who one falls in love with or what one is attracted to.

Attraction to one’s own sex is just as visceral as attraction to the opposite sex. Indeed, it makes much more sense in terms of having a cognitive feature typical of the opposite sex than being something weirdly free-floating. Though it is then a cognitive feature embedded in a different hormonal pattern. Attraction to men plus testosterone is different than attraction to men plus oestrogen, just as attraction to women plus oestrogen is different form attraction to women plus testosterone. Seeing homosexuals as having a cognitive feature more typical of the other sex also separates homosexuality from genuine para-sexualities (such as paedophilia), which are much rarer and much more clearly connected to trauma and dysfunction.

If the persistent difference in cognitive patterns between the sexes is an evolutionary advantage (and it surely has to have been to be as marked as it is), then some mechanism or mechanisms need to persist to maintain the patterns of cognitive difference by sex. If cognitive convergence between the sexes to the extent of being homosexual discourages reproduction, that would be a mechanism which would help maintain cognitive differences between the sexes. Some of the distinctiveness in physiological tendencies among homosexual men and women may point in that direction. Working out the evolutionary mathematics involved is way, way beyond my mathematical knowledge and understanding, but it would seem a useful exercise. One that gives homosexuality a much broader functional role in evolutionary dynamics that may be sufficient for it to be low instance but persistent, particularly if added to the "gay uncle" effect.

A key feature to remember about evolutionary reasoning is that we are talking about population dynamics. For instance, the persistence of psychopathy and sociopathy (or whatever the current approved labels are) at such low levels in human populations illustrate that (1) lack of empathy and normative engagement are not evolutionary advantages except as, at best, parasitic strategies on the overwhelmingly more dominant strategy(ies) using empathy and normative engagement and (2) if they are not propagating as a minor niche parasite strategy, then they are much more likely to be recurring malfunctions of the mechanisms supporting the dominant evolutionary strategy(ies).

Cultural species
That homosexual men in particular have been persistently, disproportionately involved in cultural activities is not much of a puzzle. To the extent that one does not invest in children of one’s own, the greater the pressure to invest in activities that generate social support and status independent of having one’s own children. Providing cultural services does that.

Having cognitive traits that are more “cross-sex” may well aid in creating broadly resonant cultural services, giving homosexual men both more incentive to invest in, and more capacity to successfully provide, cultural services. (That homosexual women have not been so significant is explicable in terms of the value placed on female fertility being such that taking on other roles was discouraged: especially if their fertility was women’s dominant social leverage.)

In the cultural species, having a low instance but persistent minority disproportionately willing and able to invest in cultural services would seem a clear advantage in realising the benefits of culture. Whether this can plausibly be “cashed out” genetically seems doubtful. But add in the helping to block cognitive convergence plus some level of aid to sibling reproduction, and there may well be enough selection effect to lead to the persistence of a low instance sexual minority in human populations. Which makes Darwinian Reactionary's attempt to characterise homosexuality as "selected against" with therefore straightforward consequences to how homosexuality then can, or cannot, be reasonably characterised a naively simplistic application of evolutionary reasoning.

I am absolutely for using evolutionary reasoning to think about why Homo sapiens are the way we are. Applying evolutionary reasoning to Homo sapiens is, however, a much more complex issue than the sort of naive evolutionism that Darwinian Reactionary is using.

[Cross-posted at Skepticlawyer.]

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