JD Unwin had it backwards?

What you take issue with is the anon’s crude telephone-game summary of Unwin, not Unwin’s theory itself. Unwin never characterized peak civilizations as saying, “You want a girl? Go build a cathedral and invent calculus first.” He said that under expectations of absolute monogamy, sexual energy wasn’t channeled inappropriately and unproductively, and this allowed men, single or married, to channel their energy into greater pursuits. Low sexual vice was best for the relations between the sexes, and people who built families, or at least saw how family-oriented society was, saw a future worth investing in and helped build a culture worth preserving.

The value of Unwin’s book is establishing the correlation between female premarital chastity and societal advancement. Of course Unwin’s explanation is absurd and should be ignored. I saved this book from obscurity many years ago when I was looking into related questions and got this book through interlibrary loan and scanned it. Here is my Amazon review.

I think that it might be both younger marriage without divorce and with a virgin and greater difficulty to have sex without one that contribute. Nothing for free, but a lot if you commit, helps both fertility and achievement sort of thing? Would you agree?

Unwin was clear that even primitive societies cared about female chastity. The distinct feature of societies at flourishing stages was that they enforced male restraint too: the male elites were expected to be just as abstinent before marriage and faithful within marriage as the common women, no double standard.