Referring to a person’s enduring tendencies to think, feel, and behave in a certain way, personality traits will naturally be at play when a group of individuals comes together to collaboratively solve a problem. At the individual level, personality affects what role and position one will assume within the team; at the group level, it influences the quality of team processes and thus the outcomes of teamwork (i.e., team performance). In this chapter, we first outline the most robust findings regarding the effects of the Big Five personality traits on collaborative problem solving. We then raise the question of how these findings have been used to enhance the quality of collaboration in small teams and identify two divergent approaches: The “optimal composition” approach, in which team members are selected based on their personality to optimize group functioning and maximize team effectiveness; and the “personal differences as resources” approach, wherein team members’ differences in personality are acknowledged and each one is expected to contribute according to their own personal strengths. Informed by empirical results, we discuss the advantages and limitations of these two approaches, particularly in the context of education.