3 ms·

It's well understood that testosterone levels in US young men have dramatically decreased in the last 20 years. https://pubmed.ncbi.nlm.nih.gov/32081788/ https:

It's well understood that testosterone levels in US young men have dramatically decreased in the last 20 years. https://pubmed.ncbi.nlm.nih.gov/32081788/ https://pubmed.ncbi.nlm.nih.gov/32081788/ Is it plastics? Is it other synthetic compounds like PTFE, PFOA, PFAS? I don't think the links are clear, but I'm not going to be surprised if it becomes clear these synthetic compounds are <all> negatively affecting human health. Leaded gasoline was sold between 1922 and 1996, and it's been claimed leaded gas has killed millions, and affected the IQ and mental well being of many. And the sad part is, lead was well understood as toxic before leaded gas was sold in 1922.

wcoenen 4y ago
It could just be that a factor which increases testosterone has been steadily disappearing. For example, testosterone is elevated in males after winning a fight. So if physical confrontations among males are getting less frequent for some reason (which seems like a good thing to me), then that could lead to lower testosterone levels. Another possible explanation is that we've had good birth control for a few generations now, which has eliminated the advantage of high sex drive on a males' chances of fathering children. So there is no longer a selection effect for high testosterone males. (Also seems like a good thing.) Anyway, my point is not that the above explanations are correct; just that there might be benign explanations.