Leader Personality Traits and Employee Voice Behavior: Mediating Roles of Ethical Leadership and Work Group Psychological Safety Fred O. Walumbwa Arizona State University John Schaubroeck Michigan State University The antecedents and consequences of ethical leadership were examined in a study of 894 employees and their 222 immediate supervisors in a major financial institution in the United States. The leader personality traits of agreeableness and conscientiousness were positively related to direct reports’ ratings of the leader’s ethical leadership, whereas neuroticism was unrelated to these ratings. Ethical leadership influenced followers’ voice behavior as rated by followers’ immediate supervisors. This relationship was partially mediated by followers’ perceptions of psychological safety. Implications for research on ethical leadership and means to enhance ethical behavior among leaders and nonleaders are discussed. Keywords: ethical leadership, leadership, personality, psychological safety, voice In both the mass media and the academic community, there has been a surge in interest in the ethical and unethical behavior of leaders. Although the high-profile corporate scandals in recent years may explain much of the mass media and popular focus (Walumbwa, Avolio, Gardner, Wernsing, & Peterson, 2008), ac- ademics’ interest has been piqued by fresh evidence that ethical leadership behavior is associated with both positive and negative organizational processes (e.g., Brown, Trevin ˜o, & Harrison, 2005; Mayer, Kuenzi, Greenbaum, Bardes, & Salvador, 2009) and out- comes (De Hoogh & Den Hartog, 2008). In this study, we sought to contribute to this body of knowledge by examining new ante- cedents and outcomes of ethical leadership. Brown et al. (2005, p. 120) defined ethical leadership as “the demonstration of normatively appropriate conduct through per- sonal actions and interpersonal relationships, and the promotion of such conduct to followers through two-way communication, rein- forcement, and decision-making” (for a review, see Brown & Trevin ˜o, 2006). Brown et al. argued that ethical leaders not only inform individuals of the benefits of ethical behavior and the cost of inappropriate behavior; such leaders also set clear standards and use rewards and fair and balanced punishment to hold followers accountable for their ethical conduct (see also Trevin ˜o, Brown, & Hartman, 2003). Despite the assumed importance and prominence of ethical leadership in organizations, there are still many ques- tions relating to its antecedents and consequences (Brown et al., 2005). For example, researchers know very little about why some leaders engage in the spectrum of ethical leadership behaviors and others do not. One key question is whether the likelihood of an individual being perceived as an ethical leader among subordinates can be predicted using his or her personal characteristics. Identi- fying trait antecedents will aid in the development of strategies for selecting and developing ethical leaders and determining the best means to reinforce ethical behaviors. Only a few studies have addressed the consequences of ethical leadership behavior (Brown et al., 2005; Detert, Trevin ˜ o, Burris, & Andiappan, 2007; Mayer et al., 2009). Whereas some reliable evidence from recent studies supports the idea that ethical leader- ship has a range of favorable outcomes (e.g., Brown et al., 2005; Mayer et al., 2009), Detert et al. (2007) found no relationship between ethical leadership and food shrinkage, an index of coun- terproductive behavior among restaurant employees. Some psy- chological mechanisms that may explain the more favorable ef- fects of ethical leadership have been discussed (see Brown & Trevin ˜o, 2006), but little empirical attention has been directed toward understanding the psychological processes that may differ- entiate the behavior of followers of ethical leaders from that of followers of less ethical leaders. A clearer understanding of the mechanisms by which ethical leadership influences outcomes is not only needed for the practical concerns of selecting for, devel- oping, and motivating ethical leadership; such information would also be valuable for determining whether the construct developed by Brown and Trevin ˜o and their colleagues contributes something genuinely new to leadership research and practice. With these limitations of the extant literature in mind, we had three aims in the present study. First, we identified individual traits that were expected to influence ethical leadership. We chose to focus on how leader personality relates to follower ratings of the leader’s ethical behavior for two reasons. Brown et al. (2005) and Brown and Trevin ˜o (2006) proposed that three personality traits— conscientiousness, agreeableness, and neuroticism—are plausible antecedents of ethical leadership. Personality antecedents may be uniquely suited to predicting ethical leadership, because ethical behavior reflects variation in individuals’ deep-seated values and beliefs; thus, ethical leadership should be a behavioral pattern that is very constant across situations and over time. Second, the present study contributes to the emerging theoretical and empirical research on ethical leadership by examining Fred O. Walumbwa, Department of Management, W. P. Carey School of Business, Arizona State University; John Schaubroeck, The Eli Broad Graduate School of Management and Department of Psychology, Michigan State University. Correspondence concerning this article should be addressed to Fred O. Walumbwa, Department of Management, W. P. Carey School of Business, Arizona State University, Tempe, AZ 85287-4006. E-mail: fred.walumbwa@asu.edu Journal of Applied Psychology © 2009 American Psychological Association 2009, Vol. 94, No. 5, 1275–1286 0021-9010/09/$12.00 DOI: 10.1037/a0015848 1275 This document is copyrighted by the American Psychological Association or one of its allied publishers. This article is intended solely for the personal use of the individual user and is not to be disseminated broadly.