Research on leadership emergence seeks to identify the mechanisms and variables that determine who will become leader in a group. In this paper, we aim to provide a new perspective on leadership emergence by disentangling two leadership components: (a) leadership initiative and (b) its success in attracting followers. Furthermore, in contrast to previous research on leadership emergence that focused almost exclusively on perceived leadership (usually assessed by questionnaires), we employed behavioral measures of both leadership components. In two large-scale lab studies (overall N = 754), we used an extensive set of variables as predictors of both leadership components, including not only a large number of personality traits and general intelligence, but also physical and physiological traits, such as facial attractiveness, height, waist-to-hip ratio, and testosterone. Across both studies, intelligence was the only robust predictor of both leadership components. In addition, leadership initiative was robustly predicted by extraversion and subjective competence, whereas success of leadership initiative was robustly predicted by the accuracy of the proposed answers. Importantly, several variables that were previously found to be related to leadership emergence, such as dominance, self-esteem, self-monitoring, self-efficacy, narcissism, height, and attractiveness, failed to predict any of the two leadership components in our studies.