Table 2.

Generalized linear mixed effect models (Study 1 — football fans).

Effect of game and degree of enmity on overall contributions
	Without interaction				With interaction
Predictor	b	SE	95% CI		b	SE	95% CI
Intercept	− 0.12	0.29	− 0.70	0.46	0.25	0.39	− 0.51	1.01
Game
IPD (Ref)
IPD-MD (both) (2)	1.39⁎⁎⁎	0.26	0.88	1.89	0.87⁎	0.43	0.02	1.72
Degree of enmity
None (Ref)
Weak (2)	0.71⁎	0.31	0.10	1.32	0.24	0.49	− 0.72	1.19
Strong (3)	0.45	0.29	− 0.12	1.02	− 0.09	0.48	− 1.04	0.86
Interaction
Game (2) × Enmity (2)	–	–	–	–	0.74	0.64	− 0.53	2.00
Game (2) × Enmity (3)	–	–	–	–	0.83	0.61	− 0.36	2.03
Effect of game and degree of enmity on outgroup hate
	Without interaction				With interaction
Predictor	b	SE	95% CI		b	SE	95% CI
Intercept	− 1.55⁎⁎⁎	0.33	− 2.18	− 0.91	− 0.73⁎	0.35	− 1.42	− 0.05
Game
IPD-MD (Ref)
IPD-MD positive (2)	0.51†	0.29	− 0.06	1.08	− 1.21⁎	0.59	− 2.37	− 0.05
Degree of enmity
None (Ref)
Weak (2)	0.40	0.38	− 0.35	1.14	− 0.55	0.53	− 1.60	0.49
Strong (3)	1.30⁎⁎⁎	0.35	0.61	2.00	0.00	0.49	− 0.95	0.96
Interaction
Game (2) × Enmity (2)	–	–	–	–	1.97⁎	0.80	0.41	3.53
Game (2) × Enmity (3)	–	–	–	–	2.67⁎⁎⁎	0.76	1.19	4.15

b = regression coefficients; SE = standard errors; Ref = reference group; 95% CI = 95% confidence intervals (based on the estimated local curvature of the likelihood surface). En-dashes indicate that the variable was not included in the model.

Note: All models considered the specific fan group (e.g., BD, FCS) of the decision maker and that of the opposing group as random effects.

^†p < 0.1, ⁎ p < 0.05, ⁎⁎ p < 0.01, ⁎⁎⁎ p < 0.001