任务框架及利他人格对社会折扣的影响

The Effect of Task Frames and Altruism on Social Discounting

与自我存在一定社会距离的他人获得收益或遭受损失都会给自我带来一定的效用,这种效用随着与他人间社会距离的增加而减少,该现象被称为社会折扣。本研究采用情境式选择滴定程序,探索并比较了"为他人得益而放弃自我得益"(NG-G)、"为他人不失而放弃自我得益"(NG-NL)、"为他人得益而承担自我损失"(L-G)以及"为他人不失而承担自我损失"(L-NL)4种任务框架下的社会折扣程度。结果发现:(1)4种框架下,指数模型均比双曲模型更好地描绘了被试的社会折扣规律;(2)任务框架影响社会折扣程度,"为他人不失"框架下(含NG-NL、L-NL)的折扣程度比"为他人得益"框架下(含NG-G、L-G)低;(3)任务框架与社会距离的交互作用影响社会折扣程度。随着社会距离增加,NG-G与NG-NL框架下折扣程度的差异逐渐变小,L-G与L-NL框架下折扣程度的差异也逐渐变小;(4)社会距离与利他人格的交互作用显著,高低利他人格者的社会折扣程度只在社会距离较远时存在显著差异。上述结果表明,个体不仅存在自我损失规避倾向,也存在不同程度的他人损失规避倾向。

Human beings are surrounded by social relationships often described by social distance. Generally speaking, our strongest social relationships are with those who are ＂closest＂ to us, and individuals with weaker relationships are more ＂distant＂. Social discounting refers to the phenomenon that the subjective value of another person＇s gain or loss decreases as the social distance increases. Different from temporal discounting and probability discounting which have received more attention in the realm of behavioral decision making, very few researches on social discounting have been conducted. In 2006, Jones and Rachlin studied this phenomenon for the first time under the frame of ＂I will forgo some gains in order to let another person obtain $75＂. It was found that the amount of money an individual was willing to sacrifice declined as the social distance increased. That study also revealed that the function of social discounting fitted the hyperbolic model. However, there may exist some other frames in our daily life. Therefore, in the present research, the phenomenon of social discounting is explored in four frames, including ＂I will forgo some gains in order to let another person obtain ~100＂ （NG-G）, ＂I will forgo some gains for another person to avoid losing ~100＂ （NG-NL）, ＂I will suffer some losses in order to let another person obtain ~100＂ （L-G） and ＂I will suffer some losses for another person to avoid losing ~100＂ （L-NL）. Meanwhile, this research also explored the social discounting function in the context of Chinese culture. Four experiments, including two pre-experiments and two formal experiments, were conducted. In the first pre-experiment with 117 undergraduate and post-graduate subjects, social distances between oneself and mother, a friend and a mere acquaintance were measured. The results show that the social distance between one and his/her mother is the shortest, while that between one and a mere acquaintance is the longest. Some Chinese subjects in the first pre-experiment could not understand the choice of the traditional titration procedure well, which was used by Jones and Rachlin in 2006. So a new situational choice titration procedure was tested in the second pre-experiment. The results indicate that the new titration procedure is more understandable for Chinese subjects, and therefore, is more applicable to this research. Based on the pre-experiments, two formal experiments were carried out. The first one compared social discounting between the frames of NG-G and NG-NL, and the second made comparison between the frames of L-G and L-NL. In both experiments, we conducted a 4 social distance （mother, friend, a mere acquaintance and a stranger） x2 frames （NG-G and NG-NL in the first experiment, L-G and L-NL in the second experiment） within-subject design. In addition, the subjects＇ altruism was also measured by Self-report Altruism Scale. Valid subjects recruited in the two experiments were respectively 78 and 77. The results show that： （1） in all of the four frames, exponential model is more suitable for describing social discounting than hyperbolic model among Chinese subjects; （2） task frames influence social discounting degree, which is lower in frames of NG-NL and L-NL than in frames of NG-G and L-G; （3） the interaction between social distance and task frames also has impact on social discounting degree. As social distance increases, the difference between social discounting degree in NG-G and NG-NL frame becomes smaller. This trend also exists in frames of L-G and L-NL; and （4） the interaction between social distance and altruism influences social discounting degree. Only when the social distance is long enough is there an obvious difference in discounting degree between subjects with high altruism score and those with low. In conclusion, this research suggests that people not only avoid his/her own losses, but also try to avoid others＇.