Could you elaborate here? Spurred by you and the person you're replying to painting such different pictures of what sources are out there, I took a look myself. I didn't find it so trivial to find sources backing up the person's claims.

> Most places do not have "time limits".

I couldn't find anything about slaughterhouses having lifelong limits for employees and would love a link or search term to use because it's an interesting concept to me.

> I find no evidence of abattoir workers becoming more likely to be serial killers.

I also could not find evidence for this. Here is a meta analysis of many studies, none of which mention slaughterhouse workers being more likely to be serial killers. Some studies show higher crime rates in towns with slaughterhouses, but not for violent crimes. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10009492/

> People used to kill their own animals and weren't vegetarians.

This is trivially true?