不确定性容忍度对跨期选择的影响及其情景依赖性

The Effects of Tolerance of Uncertainty on Intertemporal Choices and Its Context-dependency

采用2(不确定性容忍度:高、低)×2(跨期日期:今天/14天、今天/180天)×2(延迟奖赏值:200元、1000元)混合实验设计,探讨不同任务特征下不确定性容忍度对跨期选择的影响。结果表明:跨期日期为180天时,不确定性容忍度主效应边缘显著,不确定性容忍度与延迟奖赏值交互作用显著:在200元时低容忍度个体对延迟奖赏的折扣程度大于高容忍度个体,在1000元时无此效应;跨期日期为14天时,不确定性容忍度的主效应及其与延迟奖赏值交互作用均不显著。这表明,不确定性容忍度对跨期选择存在影响,但这种影响受到跨期日期和延迟奖赏值的调节,具有情景依赖性。

Tolerance of uncertainty （TU） is defined as individual differences in the tendency to react emotionally, cognitively, or behaviorally to uncertain situations. Many studies have shown that individuals who are low in TU appeared to have information processing biases. Evidence is accumulating that TU contributes to the symptoms associated with multiple anxiety and depressive disorders, and thus may be better understood as a transdiagnostic construct. Though TU has been related to a variety of cognitive and emotional constructs, the behavioral consequences of TU are still not clear. Time discounting refers to the reduction, at present, of the subjective value of outcomes that are temporally distant in the future. The decrease in value of a delayed reward may be due to the risk inherent in waiting： with increases in delay, there is a decrease in the certainty that the reward will be obtained. Little research has been conducted to explore the influences of the individual differences in TU on the preference in intertemporal choices. So the current study investigates how TU, money amount and temporal distance interact to predict individual differences in delay discounting using the choice titration procedure. We first hypothesized that TU significantly influenced the preference in intertemporal choices; participants with low TU had the higher degree of discounting future than participants with high TU. Second, we hypothesized that the effect of TU differed depending on task characteristics （i.e., money amount, and temporal distance）. 474 undergraduate were divided into two groups according to their scores from the intolerance of uncertainty scale, as groups with high and low TU levels in accordance with the high-low-27-percent group method. Hence, a total of 256 students were included in the study. The experiment employed a 2 （tolerance of uncertainty： high vs. low） x 2 （reward magnitude： 200 yuan vs.1000 yuan） x 2（temporal distance： 14 days vs. 180 days） mixed experimental design with money amount as the within-participants variable and the other two as between-participants variables, the dependent variable was their discount factor. Repeated Measurement ANOVA was performed to analyze the data. The results showed that： the main effects of money amount were significant; the discount factor in the large money amount level was higher than that in the small level, indicating the presence of a magnitude effect. The main effects of temporal distance were significant, indicating that the degree of discounting decreased when extending the received times of the rewards. Compared to the participants with high TU, the participants with low TU had a lower discount factor only when the rewarded money was set at 200 yuan to receive 180 days later. That is to say, individuals with low TU overestimation of time may lead to overestimation of the cost of revenue, which would result in his/her impulsive choices in intertemporal choices. There were no significant effects of TU on decision preference in intertemporal choice under the other task features. In conclusion, the present study suggests that TU can influence the preference in intertemporal choices and the influence is context-dependent, in which factors like money amount and temporal distance play a role. Implications of these results and directions for future research are discussed.