Table S1.

List of statistical analyses with the adjusted and nonadjusted RT

Adjusted RT	Nonadjusted RT
We further found that the negative effect of DLPFC thickness on prosocial giving in the DG interacted with the RT in a regression analysis of prosocial giving, including the interaction term (interaction: β = 0.355, t = 2.58, P = 0.010 for the right DLPFC; interaction: β = 0.238, t = 1.75, P = 0.081 for the left DLPFC)	Interaction: β = 0.324, t = 2.33, P = 0.020 for the right DLPFC; interaction β = 0.284, t = 2.10, P = 0.036 for the left DLPFC
The DLPFC thickness was negatively correlated with behavioral prosociality among the participants in the faster half (right: r = −0.163, P = 0.022; left: r = −0.126, P = 0.076), but the effect was nonsignificant among the slower half of participants (right: r = −0.066, P = 0.353; left: r = −0.125, P = 0.080)	Right: r = −0.180, P = 0.009; left: r = −0.148, P = 0.031; right: r = −0.022, P = 0.762; left: r = −0.090, P = 0.225
Cortical thickness of the DLPFC interacted with the overall RT (interaction, right: β = 0.824, t = 2.22, P = 0.027; interaction, left: β = 0.676, t = 1.95, P = 0.052)	Interaction: β = 0.693, t = 1.82, P = 0.069 for the right DLPFC; interaction: β = 0.622, t = 1.80, P = 0.073 for the left DLPFC
The DLPFC thickness negatively correlated with the overall prosocial behavior among the participants whose overall RT was in the faster half (right: r = −0.145, P = 0.041; left: r = −0.148, P = 0.037), but the effect was not significant among the slower half of the players (right: r = −0.079, P = 0.271; left: r = −0.087, P = 0.225)	Right: r = −0.119, P = 0.082; left: r = −0.131, P = 0.054; right: r = −0.068, P = 0.363; left: r = −0.100, P = 0.184
This negative effect of cognitive reappraisal of emotion on prosocial behavior… interacted with the overall RT (interaction: β = 0.132, t = 2.45, P = 0.015); specifically, the negative effect was significant among the faster half of the participants (r = −0.205, P = 0.002), whereas it was not significant among the slower half (r = −0.093, P = 0.172)	Interaction: β = 0.111, t = 2.07, P = 0.039; r = −0.236, P < 0.001; r = −0.029, P = 0.682
The effect of SVO prosociality on behavior interacted with the overall RT (interaction: β = −0.609, t = 5.72, P < 0.0001) (Fig. 1B). Although the effect of SVO prosociality was significant even among the slower half of participants (r = 0.533, P < 0.0001), it was much stronger among faster participants (r = 0.726, P < 0.0001)	Interaction: β = −0.548, t = 5.05, P < 0.0001; r = 0.546, P < 0.0001; r = 0.713, P < 0.0001
The consistent prosocials behaved less prosocially as they spent more time (r = −0.399, P < 0.001), and the consistent proselfs (r = 0.400, P < 0.0001) and the weak proselfs (r = 0.240, P = 0.038) behaved more prosocially as they spent more time; no significant time–behavior relationship was observed among the weak prosocials (r = −0.011, P = 0.909)	r = −0.366, P < 0.001; r = 0.366, P < 0.001; r = 0.210, P = 0.071; r = 0.025, P = 0.797
It should be noted that the RT–behavior relationship is much weaker in the weak prosocials and weak proselfs than in the consistent prosocials and consistent proselfs despite the equivalence in behavior variance [Levene’s test: F(3, 373) = 0.51, P = 0.676] and RT variance [F(3, 373) = 0.67, P = 0.568] in the four levels of SVO	RT variance [F(3, 373) = 1.07, P = 0.360] in the four levels of SVO
We first found that the effect of RT on social risk aversion interacted statistically marginally with SVO (β = 0.679, t = 1.72, P = 0.087) in such a way that consistent prosocials who were high on social risk aversion spent more time than consistent prosocials who were low on social risk aversion (r = 0.295, P = 0.007); on the other hand, the level of social risk aversion was not related to the consistent proselfs’ RT (r = 0.039, P = 0.706)	β = 0.605, t = 1.49, P = 0.137; r = 0.275, P = 0.011; r = 0.085, P = 0.408
Correlation among consistent prosocials… was not significant in these two games (r = −0.014, P = 0.901 in the DG; r = 0.060, P = 0.587 in the TG); in the other two games (the PDG and the SDG)… correlation was significant and strong both in the PDG (r = 0.308, P = 0.005) and the SDG (r = 0.350, P = 0.001); among the consistent proselfs, the correlation was negative and did not differ much between the two types of games (r = 0.007, P = 0.950 in the DG; r = −0.081, P = 0.436 in the TG; r = 0.030, P = 0.771 in the PDG; r = 0.117, P = 0.258 in the SDG)	r = −0.022, P = 0.846 in the DG; r = 0.053, P = 0.635 in the TG; r = 0.290, P = 0.008 in the PDG; r = 0.351, P = 0.001 in the SDG; r = 0.047, P = 0.648 in the DG; r = −0.018, P = 0.861 in the TG; r = 0.033, P = 0.747 in the PDG; r = 0.169, P = 0.099 in the SDG