I'm deeply confused by the worldwide drop in testosterone levels & sperm counts. It's a *huge* effect, too big to be explained by obesity. The most common explanation I see proposed is environmental contaminants. But I don't know if that's true, or which contaminants matter most.
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Replying to @s_r_constantin
greg clark noticed human lineages prone to crime tend to go extinct. you can imagine that higher incarceration rates in the 70s to present might select out high T alleles.
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Replying to @thomas_stearns @s_r_constantin
That’s a big stretch. As if violent crime was genetically determined. I’d predict is has much more to do with socialization than T levels (even if talking high TR density potential-individuals being selected out) T-decline prob related to lower age of puberty onset. But how?
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“As if violent crime was genetically determined.” You’re certain its not? Not at least influenced to a significant degree?
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I bet genes that predispose (males mostly) high levels of aggression exist. And sure genetic influence predisposing aggression may also contribute to an individual’s propensity to commit violent crimes. However, class/socialization will have more predictive power than genes.
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But genes have something to say about class/socialization too, so if that’s the case, genes still have a stronger influence than you realize. For my part, I thought testerone is pretty strongly linked to violence (and is strongly determined by genes).
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is 50 years enough to see those evolutionary pressures? For T to decline by 50% through evolution alone, in one generation the something like the top half of the T distribution would have to fail to reproduce? Any evidence that happened?
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nah. ran some numbers and there’s no plausible selection differential that could account for much of it, even over a longer timeframe. the changes in schooling since the 70s and how we socialize boys seem promising
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