A friend emailed me in response to my post below:
Interesting example with homosexuality, both because the choice of sexual behavior, pretty much the sort of thing that one would expect the strongest biological constraints on, was apparently needed to make the point about limited flexibility AND because we know historically that homosexual behavior HAS been normalized in many world cultures. The combination of these two points seems to argue strongly for human nature being flexible indeed.
I would say that the problem is precisely what you have diagnosed. We do little social engineering and much shamanism. Shamanism doesn’t work. From that you can’t conclude that engineering doesn’t work. Unsurprisingly, when people try to create large social changes or flying machines through force of will they fail. Doesn’t mean they would fail if they actually figured out how to do it.
That said, we largely don’t know how to do it, at least with respect to building utopias. Building dystopias seems to be much easier and I would say that we do know how to build fairly respectable dystopias.
On the point about homosexuality being “normalized” I think there is value in introducing biological terms such as facultative and obligate. Most of the societies which we think as “normalizing” homosexuality, such as ancient Athens, had a role for facultative homosexual behavior. Why does facultative homosexual behavior emerge? Athens was a very patriarchal society, and set the tone in ancient Greece for norms whereby elite females were excluded from public life and placed in purdah. The Athenian influence on elite Greek norms (as opposed to Spartan sexual egalitarianism necessitated by the role of women as economic managers while most men were away at war) was brought home to me when I read that in Late Antiquity one of the differences between the old Roman senatorial class and the new nobility which emerged in Constantinople was that elite women among the latter veiled themselves, adopting Greek custom.
In any case, there are other analogs for what I’m talking about. Homosexual behavior in Saudi Arabia must be framed by the fact that young heterosexual men must delay marriage due to economic vicissitudes, and pre-marital relations with women are operationally impossible. Similarly, I once lived with a general contractor who employed persons who had spent time in prison. At one point it came out that one of my roommate’s employees was bisexual, but his bisexuality was manifest only during stints in prison. Again, this shows the facultative nature of human sexual orientation. As an empirical matter our flexibility is shaped by a set of particular conditions for many traits.
Note: And yes, I do believe there are obligate homosexuals. But I generally would hold that most homosexual behavior across history was due to the type of circumstances I allude to above, and so facultative. The eliding of the differences between these two classes results in confusion in contemporary analysis.