Emotional overeating (EOE) is the tendency to eat more in response to negative emotions; its etiology in early life is unknown. We established the relative genetic and environmental influences on EOE in toddlerhood and early childhood. Data were from Gemini, a population‐based cohort of 2,402 British twins born in 2007. EOE was measured using the “emotional overeating” scale of the Child Eating Behavior Questionnaire (CEBQ) at 16 months and 5 years. A longitudinal quantitative genetic model established that genetic influences on EOE were minimal; on the other hand, shared environmental influences explained most of the variance. EOE was moderately stable from 16 months to 5 years and continuing environmental factors shared by twin pairs at both ages explained the longitudinal association.