a short post-survey that asked several follow-up questions including their assessment of group influence and their satisfaction with the outcome. Group Data. We collected data for six NFL games taking place between De- cember 2014 and February 2015. 24 groups whose transcripts showed no discussion, had users drop out prematurely, or did not make final wagers were excluded from the analysis. This resulted in 197 valid groups. The 169 groups in the five no-consensus requirement games overwhelmingly reached consensus as shown by the final outcome distributions: 132 consensus; 29 “majority rule” (only two members with same wa- ger); and 8 “deadlock” (all different). These 132 consensus groups were added to the 28 groups from the consensus-requirement game to yield the 160 groups used in our analysis below. See Supplementary Material for games and demographic attributes. Compensation and Donations. Participants were paid a flat amount for par- ticipation in the discussion: $8 during regular season play and $16 during the playoffs. Participants were informed that the $7 charity bonus they received plus (minus) their winning (losing) wager amount would be donated to the Wounded Warrior Project, a charity set up to aid wounded US military veterans. 6 Participants’ performance in raising charitable donations was tracked using an online leader board. Before presenting the results, we cast our theoretical predictions in the context of our experiment. Note that the F and U groups in Figure 1 are analogous to the favorite and underdog groups because using the game victor probability as the rhetorical issue causes the rhetorical reference to split the underdog policy side (Figure 2). We put forth the following hypotheses: H1. Favorite groups will exhibit greater group polarization than underdog Results 23