I’m sure lead levels have some effect, but how do you control for “they grew up in a completely different world”? I’d assume the latter is the primary cause of

I’m sure lead levels have some effect, but how do you control for “they grew up in a completely different world”? I’d assume the latter is the primary cause of any major behavior differences, absent some pretty breathtaking science showing otherwise. “Intelligence” is also a pretty goofy measure. If we’re talking about IQ, it’s basically “what quiz questions predict success measures, as defined by the social norms of whoever made the test”. IMO that’s a pretty sketchy way to define intelligence. Certainly not the way I think about it colloquially. To me, success and intelligence are loosely correlated but very different traits.