The study of decision-making processes represents an opportunity for developmentalists, because it involves many learning situations, in order to make better choices in the future. This chapter aims to review psychological research that highlights the role of emotions in learning during children's decision-making situations, adolescents and adults. It also aims to highlight the adaptive role of emotional processes in this learning. The term “decision-making under risk” is often used without distinguishing it from “risk-taking”. The feeling of regret and its influence on decision-making are typically studied using computerized tasks that offer a choice between two gambles represented by wheels of fortune. Understanding decision-making phenomena, and the increase in risk-taking behaviors during adolescence in an integrative approach, implies considering the social-emotional context of a decision.