Table 3.

Generalized linear mixed effect models (Study 2 — supporters of political parties).

Effect of game and degree of enmity on overall contributions
	Without interaction				With interaction
Predictor	b	SE	95% CI		b	SE	95% CI
Intercept	− 0.69⁎⁎⁎	0.19	− 1.06	− 0.33	− 1.06⁎⁎⁎	0.24	− 1.53	− 0.58
Game
IPD (Ref)
IPD-MD (both) (2)	1.36⁎⁎⁎	0.11	1.13	1.58	1.95⁎⁎⁎	0.25	1.45	2.45
Degree of enmity
None (Ref)
Weak (2)	0.02	0.17	− 0.32	0.35	0.13	0.30	− 0.46	0.72
Strong (3)	0.04	0.14	− 0.24	0.32	0.43†	0.25	− 0.05	0.92
Morality-based (4)	0.12	0.17	− 0.21	0.46	1.08⁎⁎⁎	0.29	0.50	1.65
Interaction
Game (2) × Enmity (2)	–	–	–	–	− 0.23	0.38	− 0.97	0.50
Game (2) × Enmity (3)	–	–	–	–	− 0.64⁎	0.31	− 1.25	− 0.03
Game (2) × Enmity (4)	–	–	–	–	− 1.50⁎⁎⁎	0.36	− 2.20	− 0.79
Effect of game and degree of enmity on outgroup hate
	Without interaction				With interaction
Predictor	b	SE	95% CI		b	SE	95% CI
Intercept	− 2.51⁎⁎⁎	0.28	− 3.06	− 1.95	− 2.11⁎⁎⁎	0.37	− 2.84	− 1.38
Game
IPD-MD (Ref)
IPD-MD positive (2)	1.04⁎⁎⁎	0.19	0.65	1.42	0.40	0.50	− 0.58	1.37
Degree of enmity
None (Ref)
Weak (2)	0.52	0.33	− 0.13	1.17	0.05	0.55	− 1.03	1.12
Strong (3)	0.82⁎⁎	0.29	0.26	1.38	0.54	0.43	− 0.31	1.39
Morality-based (4)	2.78⁎⁎⁎	0.32	2.15	3.41	2.08⁎⁎⁎	0.46	1.18	2.97
Interaction
Game (2) × Enmity (2)	–	–	–	–	0.75	0.69	− 0.61	2.10
Game (2) × Enmity (3)	–	–	–	–	0.45	0.57	− 0.67	1.57
Game (2) × Enmity (4)	–	–	–	–	1.38⁎	0.66	0.09	2.67

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 party (e.g., CDU, SPD) 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