Scott examines a new genetic study on missing heritability that both hereditarians and nurturists claim vindicates their position, concluding that despite the study's advances, the fundamental debate over how heritable traits like IQ actually are remains unresolved. Longer summary

This post discusses a new genetic study that attempted to resolve the "missing heritability" debate - the gap between high heritability estimates from twin studies (50-80%) and low estimates from molecular genetic studies (10-20%). The study used whole-genome sequencing to include rare genetic variants and found they could account for about 88% of expected heritability, but the actual heritability estimates themselves were only medium (30-40%). Both hereditarians and nurturists claimed victory: hereditarians because the gap was closed (proving the genes exist), nurturists because the total heritability found was still lower than twin studies suggested. Scott examines both sides' arguments, including measurement error corrections and various confounders, and concludes that despite everyone's claims, the debate remains fundamentally unresolved as different methods continue producing different estimates with no clear explanation why. Shorter summary

Scott Alexander explores new data on birth order effects among his blog readers, finding social factors likely explain firstborns' overrepresentation. Longer summary

Scott Alexander revisits the birth order effect he discovered in his blog readership in 2018, presenting new data from a 2020 survey. He confirms the original findings that firstborns are overrepresented among his readers, especially when age gaps between siblings are small. The post explores potential explanations, concluding that social factors, particularly parental attention, likely play a larger role than biological factors. This challenges some established views on the impact of early childhood experiences on adult outcomes. Scott acknowledges limitations in his analysis and calls for further research to better understand these effects. Shorter summary

Scott Alexander examines why certain families produce multiple generations of high achievers, exploring genetic, environmental, and psychological factors. Longer summary

Scott Alexander explores the phenomenon of highly accomplished families, such as the Huxleys, Darwins, and Curies, who have produced multiple generations of notable scientists, artists, and leaders. He discusses potential explanations for this trend, including privilege, genetics, and unique family environments. The post delves into the role of assortative mating, large family sizes, and the correlation between different types of talents. It also touches on the concept of a 'Hero License' - the idea that coming from an accomplished family might instill the confidence to pursue ambitious goals. Shorter summary

Scott Alexander describes 'fallacies of reversed moderation,' where moderate positions are misinterpreted as extreme opposites of the consensus view. Longer summary

Scott Alexander discusses a pattern he calls 'fallacies of reversed moderation.' This occurs when a popular consensus holds an extreme view (100% X, 0% Y), and when someone suggests a more moderate position (e.g., 90% X, 10% Y), they are accused of holding the opposite extreme view (100% Y, 0% X). He provides several examples of this pattern, including in climate change solutions, nature vs. nurture debates, and AI risk assessment. Scott explains why this pattern might occur and acknowledges its occasional validity, but argues that it's often used incorrectly. He suggests that critics should address the actual argument rather than mischaracterizing it as an extreme position. Shorter summary

The post argues that 'non-shared environment' in twin studies is often misunderstood, encompassing more than just different experiences and potentially overestimating the impact of nurture on personality and life outcomes. Longer summary

This post discusses the concept of non-shared environment in twin studies, arguing that it's often misinterpreted. The author explains that the 50% attributed to non-shared environment in many twin studies isn't solely about different experiences, but includes measurement error, random chance, and biological factors. The post breaks down various components of non-shared environment, including measurement error, luck, biological noise, immune system differences, epigenetics, and genetic mutations. The author suggests that the actual impact of different experiences (nurture) on personality and outcomes may be smaller than commonly believed, citing a review by Eric Turkheimer. The post concludes by suggesting that this interpretation could mean nature is more important than previously thought, making social interventions more challenging and genetic engineering more tempting. Shorter summary

The author revisits their belief in genetic determinism, presenting evidence that environmental factors, especially in divorce, have significant non-genetic effects on children's outcomes. Longer summary

The post discusses the author's initial belief in the genetic determinism thesis from 'The Nurture Assumption', which argues that parenting has little effect on children's outcomes compared to genetics. The author then presents evidence from divorce studies that challenge this view, showing that environmental factors, particularly family conflict, do have significant effects on children. The post reviews several studies that disentangle genetic and environmental effects of divorce, concluding that there are indeed non-genetic negative impacts of divorce on children. The author acknowledges being wrong about shared environment effects being negligible and suggests that short-term environmental impacts can have long-lasting consequences. Shorter summary

Scott Alexander argues that biological solutions to societal problems may be more effective and easier to implement than social interventions, challenging common perceptions about mutability of human characteristics. Longer summary

Scott Alexander challenges the stereotype that the Left believes human characteristics are socially determined and mutable, while the Right believes they are biologically determined and fixed. He argues that society is actually very difficult to change, while biological factors can often be more easily addressed. He provides examples such as drug abuse, obesity, and poor school performance, where social interventions have largely failed but biological solutions (like banning lead or vitamin supplementation) have shown promising results. The post suggests that we should not dismiss biological explanations and solutions to societal problems, as they may be more tractable than purely social approaches. Shorter summary

Scott Alexander defends social psychology against conservative criticism, arguing that it correctly balances situational and personality factors in human behavior, and proposes a progressive approach that leverages human nature for positive outcomes. Longer summary

Scott Alexander critiques a conservative perspective on social psychology, arguing that the field correctly recognizes the importance of both situation and personality in human behavior. He explains that social psychology's focus on situational effects doesn't negate the existence of personality traits or genetic influences. Scott uses an analogy of the heart as a series of levers to illustrate how the brain might be hard-coded for malleability. He then shares a hospital anecdote to demonstrate how progressive approaches can effectively use knowledge of human nature to create better outcomes. The post concludes by defining Scott's brand of progressivism as using knowledge of human nature to create structures that encourage prosocial behavior. Shorter summary