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44 posts found
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Jul 22, 2026
acx
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25 min 3,748 words 418 comments 198 likes
Scott shares his monthly collection of interesting links from around the internet, covering topics from Jeremy Bentham's linguistic legacy to AI developments, with characteristic commentary and fact-checking caveats. Longer summary
This is Scott's monthly 'Links' post, a curated collection of interesting articles, studies, and social media posts from around the internet. The links span a wide range of topics including historical curiosities (Jeremy Bentham's word inventions, beard-wearing persecution in 19th century America), scientific oddities (a mushroom that causes gnome hallucinations), AI developments (mathematical proofs, constrained writing, dating apps), current events (Berkeley's housing permits, GLP-1 weight retention), and cultural phenomena (the Monet/AI art prank). Scott includes his typical epistemic disclaimers about not having verified all links independently and provides commentary throughout. The post ends with a note that he accumulated too many links and will publish the second half next week. Shorter summary
Jun 23, 2026
acx
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30 min 4,501 words 355 comments 269 likes podcast (25 min)
Scott analyzes whether whole-body screening MRIs are worth it by doing a detailed cost-benefit calculation, finding they cost about $108,000 per quality-adjusted life-year saved (right around the threshold of cost-effectiveness), and argues that while rich people immune to anxiety might benefit, most people claiming to be rational about medical decisions probably aren't. Longer summary
Scott performs a detailed cost-benefit analysis of whole-body screening MRIs in response to controversy over medical experts recommending against them. Using rough order-of-magnitude estimates, he calculates that screening 1,000 people saves about 32 quality-adjusted life-years (QALYs) at a cost of $2.7 million plus time and anxiety costs, working out to about $108,000 per QALY saved—right at the threshold of cost-effectiveness. He explores whether rich people who don't care about money should get screened, finding a plausible case but with many caveats about unknown factors that could swing the calculation either way. He then applies this analysis to Midjourney's proposed ultrasound scanner, finding it's unlikely to be clearly better than MRI. The post ends with a warning that people who think they're rational enough to ignore false positives are often the same people making irrational medical decisions based on contrarian appeals. Shorter summary
Jun 26, 2025
acx
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68 min 10,491 words 669 comments 456 likes podcast (62 min)
Scott explores the 'missing heritability' problem in genetics, where twin studies show traits like IQ and educational attainment are highly heritable but newer genomic methods find much lower heritability, analyzing various potential explanations for this discrepancy. Longer summary
The post examines the 'missing heritability' problem in genetics, where twin studies consistently show behavioral traits like IQ and educational attainment are substantially heritable (around 40-60%), while newer genomic methods find much lower heritability (around 15-20%). Scott reviews the history of behavioral genetics research, explains various study methodologies and their potential biases, and analyzes different hypotheses for this discrepancy. He examines whether twin studies might be flawed, whether newer methods might be missing important genetic effects, and whether educational attainment might be an unusually problematic trait to study. While acknowledging remaining mysteries, he tentatively concludes that twin studies are probably largely correct and that newer methods may be missing rare variants and genetic interactions. Shorter summary
Feb 27, 2025
acx
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45 min 6,840 words 933 comments 212 likes podcast (43 min)
Scott shares 50 diverse links covering topics from AI developments to policy changes, with commentary on current events, research findings, and societal trends. Longer summary
In this monthly links roundup, Scott Alexander covers a wide range of topics including AI developments, public policy changes, scientific research, and current events. The post follows a numbered format presenting each item with Scott's characteristic analysis and often humorous commentary. Notable topics include AI safety developments, changes in government policy, climate change updates, and various social and technological trends. The tone alternates between analytical and personal reflection, particularly when discussing potentially concerning political developments. Shorter summary
Aug 13, 2024
acx
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29 min 4,403 words 567 comments 1,016 likes podcast (27 min)
Scott Alexander examines the surprisingly broad effects of GLP-1 drugs like Ozempic, exploring their mechanisms and speculating on why they seem to impact so many different conditions. Longer summary
Scott Alexander explores the wide-ranging effects of GLP-1 receptor agonist medications like Ozempic, which are approved for diabetes and obesity but show promise for many other conditions. He delves into the mechanisms behind their effects on diabetes, weight loss, and addiction, speculating on why these drugs seem to have such broad impacts. The post discusses how GLP-1 drugs work in the brain to reduce hunger and dampen reward systems, potentially explaining their effects on addiction. Scott also touches on their anti-inflammatory properties and potential benefits for neurodegenerative diseases, while cautioning that some reported effects may not replicate. Shorter summary
Jul 19, 2024
acx
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76 min 11,773 words 645 comments 242 likes podcast (79 min)
The review examines Daniel Everett's 'How Language Began', which challenges Chomsky's linguistic theories and proposes an alternative view of language as a gradual cultural invention. Longer summary
This book review discusses Daniel Everett's 'How Language Began', which challenges Noam Chomsky's dominant theories in linguistics. Everett argues that language emerged gradually over a long period, is primarily for communication, and is not innate but a cultural invention. The review contrasts Everett's views with Chomsky's, detailing Everett's research with the Pirahã people and his alternative theory of language origins. It also touches on the controversy Everett's work has sparked in linguistics and its potential implications for understanding language and AI. Shorter summary
Jul 12, 2024
acx
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72 min 11,039 words 133 comments 171 likes podcast (58 min)
A review of 'The Family That Couldn't Sleep' by D. T. Max, discussing its exploration of prion diseases and their impact, with updated perspectives on the book's conclusions. Longer summary
This review discusses 'The Family That Couldn't Sleep' by D. T. Max, a book about prion diseases published in 2006. The review covers the book's exploration of various prion diseases, including fatal familial insomnia, kuru, mad cow disease, and chronic wasting disease. It highlights the book's focus on the historical, scientific, and cultural aspects of these diseases, as well as the key figures involved in prion research. The reviewer also provides updated information and critiques some of the book's conclusions in light of more recent research. Shorter summary
May 15, 2024
acx
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28 min 4,208 words 829 comments 309 likes podcast (25 min)
The post explores the Far Out Initiative's goal to eliminate suffering through biotechnology, inspired by a pain-free woman and David Pearce's philosophy. Longer summary
This post discusses the Far Out Initiative, a project aimed at eliminating suffering through biotechnology. It begins by introducing Jo Cameron, a woman genetically incapable of feeling pain or anxiety, and explores the philosophical implications of her condition. The post then delves into David Pearce's suffering abolitionism philosophy and his practical approaches to ending suffering. Finally, it describes the Far Out Initiative's current efforts, led by Marcin Kowrygo, to create suffering-free animals through genetic engineering and potentially extend this to humans in the future. Shorter summary
May 10, 2024
acx
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40 min 6,106 words 169 comments 77 likes podcast (39 min)
Scott Alexander summarizes comments on his healthcare effectiveness debate with Robin Hanson, including clarifications, study author responses, and reader perspectives on various healthcare topics. Longer summary
This post highlights comments on Scott Alexander's recent discussion with Robin Hanson about healthcare effectiveness. It includes responses from Robin Hanson clarifying his position, comments from the authors of a study on health insurance and mortality, and various reader perspectives on healthcare, medical waste, and specific medical treatments. The post touches on topics like the statistical analysis of healthcare studies, the value of preventive medicine, and the complexities of measuring healthcare outcomes. Shorter summary
Apr 09, 2024
acx
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119 min 18,355 words 694 comments 128 likes podcast (99 min)
Scott Alexander responds to comments on his COVID-19 origins debate post, addressing criticisms and maintaining his support for the zoonosis theory. Longer summary
Scott Alexander provides a detailed response to comments and criticisms of his previous post on the COVID-19 origins debate. He addresses arguments against zoonosis, clarifies misunderstandings, and discusses the methodologies used by various parties in the debate. He maintains his position favoring zoonosis over lab leak, while acknowledging the complexity of the issue and the ongoing nature of the debate. Shorter summary
Mar 28, 2024
acx
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118 min 18,207 words 905 comments 369 likes podcast (95 min)
Scott Alexander reviews a $100,000 debate on COVID-19 origins, where the zoonotic hypothesis unexpectedly won against the lab leak theory. Longer summary
Scott Alexander reviews a debate on the origins of COVID-19 between Saar Wilf, who supports the lab leak hypothesis, and Peter Miller, who argues for zoonotic origin. The debate was part of a $100,000 challenge by Wilf's Rootclaim project. Miller won decisively, with both judges ruling in favor of zoonotic origin. Alexander analyzes the debate format, arguments, and aftermath, discussing issues with Bayesian reasoning, extreme probabilities, and the challenges of resolving complex scientific questions through debate. Shorter summary
Feb 28, 2024
acx
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7 min 970 words 593 comments 236 likes podcast (7 min)
Scott Alexander explores the misconception of utilitarianism, arguing that many common political actions are more ethically questionable than his own 'utilitarian' views. Longer summary
Scott Alexander discusses the perception of utilitarianism and how it's often misunderstood. He argues that many common political actions, which violate ethical rules for a supposed greater good, are not seen as utilitarian. Meanwhile, his own views labeled as 'utilitarian' are often less extreme. He suggests this disparity stems from people's discomfort with applying calculations to morality, rather than from the actual ethical implications of different actions. Shorter summary
Jan 03, 2024
acx
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17 min 2,509 words 377 comments 365 likes podcast (15 min)
Scott Alexander proposes a theory of depression as a recalibrated happiness set point, drawing parallels with fever and anorexia, to explain why depressed people seek out sad stimuli. Longer summary
Scott Alexander explores the puzzling behavior of depressed people preferring sad music, despite it making them feel worse. He proposes a theory based on control theory and set points, comparing depression to conditions like fever and anorexia. The post suggests that depression might involve a recalibrated happiness set point, where the body defends an abnormally low mood through both biological and behavioral mechanisms. Scott also discusses potential research directions and connects this theory to predictive coding concepts. Shorter summary
Oct 04, 2023
acx
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22 min 3,400 words 401 comments 107 likes podcast (22 min)
Scott Alexander examines recent studies on the Fraternal Birth Order Effect, finding evidence for a broader sibling birth order effect on homosexuality, though its exact nature and mechanism remain debated. Longer summary
Scott Alexander reviews recent studies on the Fraternal Birth Order Effect (FBOE), which suggests that men with more older brothers are more likely to be gay. He discusses three key studies: Frisch and Hviid's large-scale Danish study that found no clear FBOE, Vilsmeier et al.'s meta-analysis that questioned the statistical validity of previous FBOE claims, and Ablaza et al.'s extensive Dutch study that found a significant effect of older siblings (both brothers and sisters) on homosexuality. Scott concludes that while the FBOE hypothesis has been forced to evolve, the core idea that more older siblings increases the likelihood of homosexuality seems to stand, though the biological mechanism remains uncertain. Shorter summary
Aug 23, 2023
acx
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16 min 2,373 words 241 comments 147 likes podcast (14 min)
Scott Alexander investigates the claim that children learn languages faster than adults, finding it partially true but more nuanced than commonly believed. Longer summary
Scott Alexander examines the claim that children learn languages faster than adults, finding it to be partially true but more complex than commonly believed. He explores various aspects of language acquisition, including critical periods for first language learning, age effects on second language learning, and differences in learning rates between children and adults. The post concludes that while children seem to pick up second languages faster than adults, this advantage is not as clear-cut as often thought, and factors like exposure, motivation, and declining learning rates with age play significant roles. Shorter summary
May 24, 2023
acx
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45 min 6,823 words 411 comments 290 likes podcast (39 min)
Scott Alexander examines hypergamy in modern marriages, finding educational hypergamy has reversed while income hypergamy persists, with strong class homogamy for both genders. Longer summary
Scott Alexander examines the concept of hypergamy, particularly focusing on educational and income differences in heterosexual marriages. He finds that while educational hypergamy (women marrying more educated men) has reversed due to women's increasing educational attainment, income hypergamy (women marrying higher-earning men) persists. The post explores various studies on class, income, and educational matching in marriages, discusses the role of physical attractiveness, and touches on hypergamy in same-sex relationships. Scott concludes that class homogamy is strong for both genders, with looks playing a smaller role than often assumed in mate selection. Shorter summary
Feb 17, 2023
acx
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31 min 4,739 words 225 comments 156 likes podcast (27 min)
Scott Alexander reviews the evidence for declining sperm counts, discussing major studies, criticisms, and potential causes, while remaining uncertain about the true extent and reasons for any decline. Longer summary
Scott Alexander examines the evidence for declining sperm counts worldwide, discussing the major studies, potential causes, and criticisms of the hypothesis. He explores the methodology of sperm count studies, regional variations, possible explanations like plastics and pesticides, and animal data. While acknowledging the noisy data and potential confounders, he concludes that there's suggestive evidence for a decline but remains uncertain about its magnitude and causes. Shorter summary
Oct 26, 2022
acx
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26 min 3,901 words 44 comments 34 likes podcast (25 min)
Scott responds to various comments on his article about supplement labeling, addressing concerns about the industry and providing additional context and analysis. Longer summary
This post is a highlights reel of comments on Scott's previous article about supplement labeling. It covers various points raised by commenters, including skepticism about the supplement industry, concerns about heavy metal contamination, and a defense from the founder of LabDoor. Scott responds to each comment, providing additional context, analysis, and sometimes his own perspective on the issues raised. The post touches on topics such as the efficacy of supplements, the trustworthiness of supplement testing companies, and the potential risks associated with certain types of supplements. Shorter summary
Jul 01, 2022
acx
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24 min 3,695 words 576 comments 88 likes podcast (31 min)
Scott Alexander shares 57 diverse links on topics including politics, science, technology, and culture, providing brief summaries and commentary on each. Longer summary
This post is a collection of 57 diverse links covering various topics including politics, science, technology, culture, and society. Scott Alexander briefly summarizes each link, often adding his own commentary or thoughts. The links range from scientific studies and political polls to interesting cultural phenomena and technological advancements. Some notable topics include AI development, environmental issues, mental health, and social trends. Shorter summary
May 27, 2022
acx
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31 min 4,689 words 275 comments 155 likes podcast (33 min)
A review of 'The Anti-Politics Machine' by James Ferguson, discussing its critique of development projects and implications for Effective Altruism. Longer summary
This post reviews 'The Anti-Politics Machine' by James Ferguson, which critiques development projects in Lesotho. The reviewer highlights two key ideas: the concept of 'development discourse' that leads to misinterpretation of local contexts, and the 'anti-politics machine' critique of technocratic decision-making. The review discusses how these ideas apply to modern development economics and Effective Altruism, suggesting the need for more qualitative research, emphasis on local context, and consideration of political implications in charitable work. Shorter summary
May 18, 2022
acx
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16 min 2,400 words 234 comments 160 likes podcast (19 min)
Scott Alexander evaluates silexan, a lavender-based anxiety supplement, finding promising but potentially biased evidence, and recommends cautious trial use. Longer summary
Scott Alexander reviews the evidence for silexan, a lavender-derived supplement claimed to be highly effective for anxiety. He examines the studies, noting that most are by one researcher with conflicts of interest, but finds the methodology generally sound. He also considers circumstantial evidence, including animal studies and anecdotal reports. While cautioning about the lack of independent research, Scott concludes that silexan is worth trying due to its low risk and potential benefits, and predicts a 50% chance it will prove as effective as SSRIs for anxiety in future independent studies. Shorter summary
Apr 22, 2022
acx
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26 min 3,883 words 159 comments 84 likes podcast (28 min)
Scott Alexander critiques Ben Hoffman's arguments about Vitamin D dosing, maintaining that it is primarily a bone-related chemical with limited evidence for other benefits. Longer summary
Scott Alexander responds to Ben Hoffman's critique of his views on Vitamin D dosing. He argues that ancestral populations likely received much less Vitamin D from sunlight than Hoffman suggests, and that the doses used in most studies are appropriate. Scott reviews the literature on Vitamin D dosing, discusses various recommendations and debates within the medical community, and explains why he remains skeptical of claims about Vitamin D's non-skeletal benefits, including for COVID-19 treatment. Shorter summary
Apr 13, 2022
acx
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80 min 12,326 words 201 comments 102 likes podcast (91 min)
Scott Alexander examines obscure pregnancy interventions that may improve child outcomes, rating them by evidence quality and potential impact. Longer summary
Scott Alexander reviews various obscure pregnancy interventions that could potentially improve child outcomes, particularly IQ. He rates them in tiers based on evidence strength and potential impact, with Tier 1 being most strongly supported. Key interventions discussed include embryo selection, choline supplementation, avoiding stress and certain substances, and optimizing birth timing. He emphasizes these are extreme measures not meant to induce guilt, and that standard pregnancy advice is still most important. Shorter summary
Nov 29, 2021
acx
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4 min 554 words 179 comments 88 likes podcast (6 min)
Scott Alexander analyzes prediction market forecasts about the Omicron COVID-19 variant, discussing its potential transmissibility, lethality, and prevalence. Longer summary
Scott Alexander discusses predictions about the Omicron variant of COVID-19 using data from prediction markets, particularly Metaculus. He examines forecasts on the variant's transmissibility (R0), lethality compared to Delta, and its expected prevalence in the US. The post highlights that Metaculus predicts Omicron to be more transmissible than Delta, with a 34% chance of being deadlier, and likely to become the dominant US variant by mid-March. Scott concludes with a humorous tweet about the rapid emergence of new variants. Shorter summary
Nov 17, 2021
acx
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109 min 16,786 words 2,113 comments 442 likes podcast (128 min)
Scott Alexander analyzes ivermectin studies for COVID-19, finding most positive results likely due to methodological flaws, fraud, or confounding by parasitic infections. Longer summary
Scott Alexander provides an in-depth analysis of ivermectin studies for COVID-19 treatment, examining methodological issues, potential fraud, and confounding factors. He concludes that ivermectin likely doesn't significantly reduce COVID mortality except potentially in areas with high parasitic worm infections. The post explores broader issues around scientific credibility, fraud detection, and public trust in science. Shorter summary
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