I really liked Pinker's book, but that was imho one of the weaker sections. For one thing, it more or less says that violence dropped because of "cultural shifts", which is more or less a description of what happened, not an explanation.
Interesting read.
In Enlightenment Now, Pinker attributes the spike in opioid overdoses and suicides to "the druggy Baby Boomer cohort reaching middle age".
(Similarly, the same cohort reached prime crime-committing age during the 1960s-80s spike in violence.)
Lead and Roe v Wade are often discussed, but it's one of those issues that's really hard to gain confidence about any particular explanation. It appears likely that both played a role, but to what extent is more difficult to say.
Roe v Wade is pretty far out there, but lead exposure has a lot of decent correlational data from different regions, since it was phased out around the country and around the world at different times.
Roe v Wade is not _that_ far out there. It explains state-level differences for when the decline began, for example. I'm not saying it's a slam dunk, but it's got some reasonable supporting evidence, enough to at least not be considered "out there".
You may be right; I recall, though, hearing some fairly convincing counter-arguments at the time the first Roe v Wade hypothesis was floated. But maybe there's been more research since.
The biggest argument I've heard since then was that, while the abortion rate has gradually declined again since then, the crime rate has not gone back up.
