tag:blogger.com,1999:blog-1802321156556032652.post8381871904044716333..comments2024-01-10T00:37:30.059-05:00Comments on <i>Sexology Today!</i>: Looking on the bright side vs. misrepresenting evidence: WPATH review of outcomes of medicalized minorsJames M. Cantor, PhDhttp://www.blogger.com/profile/07213273477527448472noreply@blogger.comBlogger1125tag:blogger.com,1999:blog-1802321156556032652.post-23338817744253354252023-03-25T05:20:22.091-04:002023-03-25T05:20:22.091-04:00Have you heard about that genetic study showing th...Have you heard about that genetic study showing that the age at average conception over prehistory has been about 23? I was thinking that this could be used to estimate the age ancestral girls had their first pregnancy. If the age at average conception for various modern HGs were computed we could see which ones are closest to the ancestral value of 23.<br /><br />In the !Kung and Hadza girls have menarche at about 16 and their first conception about 20, so the average conception must be much higher than 23 and closer to 30. What we see in these tribes is probably not as representative of the ancestral reproductive pattern as many anthropologists believe. The girls in these tribes seem to be suffering delayed menarche due to living in poor habitats. Ancestral humans appear to have evolved in the fertile African wetlands eating a diet of predominately meat. They were better nourished than the !Kung and Hadza and the girls almost certainly had menarche earlier.<br /><br />At one point in prehistory the average went down to 21. This is clearly not compatible with the first conceptions happening at about 20. The average can't be the same as the first unless all the girls were having just one baby and then dying or hitting menopause. Completely unrealistic, of course. <br /><br />In the Pume tribe in the Amazon girls have menarche at 12 and first conception about 14. The age at average conception for this tribe probably works out to be close to 23. I haven't rigorously analyzed any statistics at this point, I'm just ballparking it and my hunch is that this reproductive pattern, menarche at 12 and first conception at 14, is probably closer to that of ancestral humans.<br /><br />The age that ancestral girls started reproducing is relevant to the evolution of men's sexual preferences. Since humans form long-term bonds and men try to monopolise the fertile years of the females, we'd expect men to have evolved an instinctive preference for females just prior the beginning of their reproductive lifespan. If this was at 20 in ancestral times men would have a preference for females just under 20. If it was 15, we'd expect men to have an instinctive preference for females a little under 15. I believe the evidence points to the latter though it's difficult to discuss this in public due to our taboos over attraction to minors.<br /><br />Link to study: https://pubmed.ncbi.nlm.nih.gov/36608127/Anonymousnoreply@blogger.com