Scott Alexander argues that underpopulation concerns are overstated and likely irrelevant due to expected technological changes by 2100. Longer summary

Scott Alexander argues against worries about underpopulation, stating that while there may be some demographic shifts and challenges, they are not as dire as some claim. He presents data showing global population will continue to grow until 2100, and even countries with declining populations will still have substantial numbers. He discusses potential issues like age pyramid concerns and innovation slowdowns, but argues these are either manageable or likely to be overshadowed by technological changes. Scott concludes that long-term population projections are largely irrelevant due to the likelihood of transformative technological changes before 2100. Shorter summary

Scott responds to authors of a Victorian intelligence paper, remaining skeptical of their findings and addressing critiques of his original post on IQ change speeds. Longer summary

Scott Alexander responds to the authors of a paper on Victorian intelligence who replied to his earlier critique. He remains skeptical of their findings, arguing that the Victorian sample was still more elite than modern comparisons, even when broken down by occupation. Scott also addresses a point from his original critique about the speed of IQ changes, acknowledging some validity to commenters' objections but explaining his reasoning. He concludes by suggesting that concerns about dysgenic effects on IQ may be overblown given the likely timeframe for genetic engineering or transfer to nonbiological life. Shorter summary

Scott Alexander debunks a study claiming Victorians were smarter than modern people, showing it's based on flawed data comparison and ignores crucial factors like selection bias and demographics. Longer summary

Scott Alexander critiques a study claiming Victorians were more intelligent than modern people based on reaction time measurements. He argues the study's conclusion is flawed due to significant selection bias in the Victorian data, which primarily came from wealthy, educated individuals. The modern data, in contrast, was more representative of the general population. Scott points out that the difference in reaction times can be explained by sampling from the top 20% of Victorian society versus a broader modern sample. He also highlights how the study ignores important factors like race and regional variations in IQ, which could further account for the observed differences. Scott concludes by urging readers not to cite this study as evidence for declining intelligence or civilization. Shorter summary