Terrorism poses a significant challenge for psychology. Motivation to engage in such violent and anti-nonnative behavior has yet to be understood. The two studies described in the present thesis examined what psychological motivations might account for peoples' involvement in terrorism. Study 1 explored the collective narratives of participants with ties to the Liberation Tigers of Tamil Eelam. Participants' narratives conveyed the explicit theme of justice and the implicit theme of identity as motives for extreme violence. Based on these findings, study 2 investigated if social identity and justice motives would exceed a control condition in inciting participation in terrorism. In a laboratory setting, participants were recruited to partake in a fictitious terrorism plot. Recruitment that emphasized social identity motives was relatively more compelling for participants than justice motives. Results for both studies warrant further research into the psychological role that justice and identity might play in the use terrorism.