Is there an entrepreneurial personality and does it appear early in life? We provide a new answer on this question by using the so-called Type A behavior traits (Aggression, Leadership, Responsibility, and Eagerness-Energy), measured in childhood and adolescence, and examining their relationship to self-employment propensity in adulthood. Using data from the Young Finns Study linked to the Finnish Longitudinal Employer-Employee Data and the Longitudinal Population Census of Statistics, our results show that the early-life Leadership-dimension is significantly associated with a higher likelihood 1) of becoming self-employed later in life and 2) of being more successful as an entrepreneur, as approximated by sales. Our results also reinforce the prior evidence on the intergenerational transmission of entrepreneurship.