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