Bringing together self-determination theory, intergroup theories based on the social identity approach, and normative approaches, three studies conducted among hockey fans tested if social norms and social identity predict greater self-determined motivation to engage in derogatory behaviours against an outgroup team and higher frequency of these behaviours. Higher self-determination was conceptualised as an indicator of internalisation. In Study 1, hockey fans who identified more strongly as fans of the Montreal Canadiens (N = 181) displayed a stronger positive association between the perceived norm in favour of outgroup derogation and self-determined motivation to engage in derogatory behaviours against fans of an outgroup team. This interaction also emerged on the frequency with which the derogatory behaviours were enacted. In Studies 2 and 3 (Ns = 105 and 116), this norm by social identity interaction was replicated on both the self-determination and the frequency outcomes for fans of a diversity of teams in the National Hockey League. In Study 3, these findings were observed over and above a manipulation that framed derogatory behaviours as being either harmful or beneficial. Results are discussed in light of motivational theories, normative approaches, and intergroup theories based on the social identity approach. Copyright © 2014 John Wiley & Sons, Ltd.