Previous research in the activity area has found that descriptive norms can influence individual activity (Crozier, 2014; Priebe & Spink, 2014; 2015). While important, studies examining other important outcomes in the activity area have not been conducted. For example, no research has examined whether normative information can be used to influence athletes' intentions to intervene with other teammates. In an effort to address this gap in the literature, the purpose of the current experiment was to examine whether descriptive norms, that were either supported by a coach or not, would influence a player’s intentions to intervene when teammates made technical errors or did not exert enough effort. Canadian adult soccer players (N = 106) were recruited to participate in this online experimental study. Participants were assigned to one of three conditions: normative (teammates intervene)/coach support, normative (teammates intervene)/coach not support, or attention control. Participants in both of the normative conditions read two short vignettes describing how the players and coach on a hypothetical soccer team responded to a teammate’s technical mistakes and lack of effort, respectively. While imagining themselves as a member of this hypothetical team, participants then rated their intentions to intervene with other members of this team. Results from ANCOVAs (controlling for previous intervening behaviour) revealed different results for intentions to intervene following technical mistakes versus lack of effort. Results for technical mistakes revealed a significant main effect for condition F(2, 102) = 4.98, p 0.05, adj Cohen’s d = 0.13). There was no significant main effect for condition with respect to teammates exhibiting a lack of effort F(2, 95) = 1.82, p > 0.1). Results from this experiment provide initial evidence that descriptive norms supported by a coach may influence players' intentions to intervene when a teammate makes a mistake
