SummaryThis research examines whether the relationship between an individual's personality and their behavior within a team is contingent on the team's overall perception of its capability. Individuals were peer-rated on the extent to which they displayed interpersonal and performance management teamwork behaviors over the course of an 8 week business simulation. The personality trait of agreeableness predicted interpersonal teamwork behavior, while the personality traits of conscientiousness and core self-evaluation (CSE) predicted performance management behavior. Multilevel analysis showed that collective efficacy influenced the extent to which an individual engaged in both types of behavior, and was also a cross-level moderator of the relationship between agreeableness and interpersonal behavior and the relationship between CSE and performance management behavior. This study takes a multilevel approach to examine the possibility that the relationship between an individual's personality and their behavior within a team is contingent on the team's perception of its capability. This shared perception of team capability, known as collective efficacy, has been defined as ''a group's belief in their conjoint capabilities to organize and execute the courses of action required to produce given levels of attainments'' (Bandura, 1997, p. 477 A substantial volume of research has also emerged on the role of personality in teams, and much of this research has centered on the relationships between personality traits, under different forms of compilation, and team performance (e.g., Barrick et al., 1998). Thus, we know a great deal about how personality composition, such as the average of, or variance between, team members' scores on a trait relates to team outcomes (Bell, 2007). What we know less about, however, is how individual personality and team-level characteristics (such as collective efficacy) interact to influence how individuals behave in teams. This study focuses on linkages between personality traits and individual behavior, rather than team-level composition effects because although research on team composition has demonstrated that team member personality is associated with team performance, it has provided less insight into the mediating processes through which personality is linked to performance (a noteworthy exception is a study by Stewart, Fulmer, & Barrick, 2005).One of the primary ideas we advance is that collective efficacy, which is a team-level emergent state, influences the relationship between individual traits and individual behavior. As we discuss below, collective efficacy exerts cross-level effects on the relationship between personality and behavior by encouraging (or discouraging) the display of trait-relevant behaviors. Treating collective efficacy as a variable that contextualizes individual personality to behavior relationships is consistent with the definition of context put forth by Johns (2006); specifically, that context refers to ''situational opportunities and constraints that affect...