Cultural psychology could have been changing too. Rates of corporeal punishment going down resulting in less violent behavior. Data in this study shows a 30 percentage point drop in rates of spanking, and every study done on spanking has shown it is at best neutral but commonly creates negative outcomes

http://unh.edu/ccrc/pdf/CV358%20-%20Published%202019.pdf

I much prefer incorporeal punishment. When the ghost tries to whack you, you just act like it hurts and you're good

Key word there being “selecting”, which makes this a pretty implausible explanation for something we can observe over a couple decades.

Unless production is controlled by the environment rather than strictly genetic factors.

This wouldn't be a genetic argument then.

So then totally irrelevant to the silver fox experiment.

Hormone production is something that the body controls. It doesn't require multiple generations or genetic selection.

I don't get what you're saying, every phenotype is something "that the body controls."

The point is that it's not a genetically determined effect.

Testosterone in your body fluctuates throughout the course of a single day, based on what happens to you in that day.

So at a societal level, we'd expect some general zeitgeist based average to fall out of other factors, potentially.

This only makes sense if your underlying assumption is that the less violent are reproducing more offspring now. Your reference study merely shows that the phenotypical traits have a strong correlation with the behavior traits (in at least foxes). This selection requires offspring but its seems the parent is referencing a hormonal change due to social behavior.

I agree with the premise, that social and environmental norms can influence hormones, but the fox study is a different phenomenon altogether.

>This only makes sense if your underlying assumption is that the less violent are reproducing more offspring now.

I wouldn't rule it out. After a generation of anti-bullying and zero tolerance schools have gotten pretty good at making sure anyone with even the slightest violent tendencies is primed to be caught up in "the system" by the time they're done and we've thrown the "fuck the government I smoke what I want" crowd in prison.

Agreed. I wouldn't rule it out for mid to long term trends.

Estrogen emulating particles [1] are a candidate considering the short time intervals from article.

[1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3222987/