We use longitudinal data from children growing up in four developing countries (Peru, India, Vietnam, Ethiopia) to study the relationship between height at the age of 7–8 and a set of psychosocial competencies measured at the age of 11–12 that are known to be correlated with earnings during adulthood: self-efficacy, self-esteem and aspirations. Results show that a one standard deviation increase in height-for-age tends to increase self-efficacy, self-esteem and aspirations by 10.4%, 6.4% and 5.1%, respectively. We argue that these findings are likely to be informing of an underlying relationship between undernutrition and the formation of non-cognitive skills.