Abstract
Educational attainment is a major determinant of health, wealth, and relationship quality, making it key for human flourishing. A diverse set of major childhood disruptions are known to predict poorer academic performance. Here we propose that childhood unpredictability constitutes a latent dimension of early-life environments underpinning these effects, suggesting everyday instability, in addition to major disruptions, should determine educational success. To test this hypothesis, we link population-wide Danish administrative records with a validated survey measure to quantify individuals' life disruptions, both major and minor. Among 2,793 respondents, greater unpredictability is associated with lower grade point averages and reduced high school completion, even after accounting for parental socioeconomic status and observed major life disruptions. Our finding that childhood unpredictability alters educational success, suggests a pathway through which disadvantage may be transmitted across generations and highlights everyday unpredictability as a potential target for interventions aimed at improving social mobility.