I'm not saying the conclusion is accurate, but there is a correlation between mean reaction time and intelligence in humans. That doesn't mean that you can extr

I'm not saying the conclusion is accurate, but there is a correlation between mean reaction time and intelligence in humans. That doesn't mean that you can extrapolate intelligence from reaction time of Victorian era people. Their reaction time could be better for other un-accounted-for reasons. But it's not like the researchers just made up a link between reaction time and intelligence out of thin air because it sounded true. There really is a correlation between the two. I would say this is weak evidence in favor of Victorians having higher intelligence, and insufficient to actually draw that conclusion. But still, evidence.