Have you considered that the educational level in the developing world has increased dramatically from a low base, while pollution had so far been manageable in

Have you considered that the educational level in the developing world has increased dramatically from a low base, while pollution had so far been manageable in most cities until the most recent couple of decades? When one increased the average education level by something like 5-10 years, as was the case in many Asian countries in the last century, it is not surprising there was a significant increase in intelligence. Thankfully the effect of pollution has not been drastic enough to negate all of those gains. It still does not mean we should neglect its likely significant negative impact. From the paper: > Cutting annual mean concentration of particulate matter smaller than 10 μm (PM10) in China to the Environmental Protection Agency’s standard (50 μg/m3) would move people from the median to the 63rd percentile (verbal test scores) and the 58th percentile (math test scores), respectively.