Scott Alexander discusses a replication of his nootropics survey, expressing skepticism about the results due to potential placebo effects and biases in participant ratings. Longer summary

Scott Alexander discusses a replication of his 2020 nootropics survey by the blog Troof, which gathered data from 1981 subjects using a recommendation engine. While the results largely align with Scott's original survey, he expresses some skepticism about the findings. He notes that addictive or illegal substances, difficult lifestyle interventions, and fancy high-tech chemicals tend to rank higher, which could be due to both actual effectiveness and placebo effects. Scott highlights concerns about psilocybin microdosing's high ranking despite studies showing its ineffectiveness, and the low ranking of SAMe despite its proven effectiveness in clinical trials. He suggests that a simple model based on factors like difficulty of obtaining the substance and perceived novelty could largely predict the survey results, questioning whether any findings truly stand out beyond these factors. Shorter summary

Scott Alexander partially retracts his previous post on animal value and neural number after a commenter's larger survey yielded different results. Longer summary

Scott Alexander partially retracts his previous post about animal value and neural number. A commenter, Tibbar, replicated Scott's survey using Mechanical Turk and obtained different results with a larger sample size. Scott acknowledges that while Mechanical Turk users might not be the ideal sample and some responses seem rushed, it's difficult to claim his original results represent a universal intuitive understanding. He explains that his original sample was more informed about animal rights issues. Scott adds this to his Mistakes page and considers including a similar survey in the future, hoping readers will have forgotten about this retraction. Shorter summary