Abstract: Intertemporal choice is the individual balances costs and benefits of decision-making process which occurred at different times. An important finding in intertemporal choice is time discounting which is that compared to gains (or losses) in the present, people always give less weight on gains (or losses) in the future. That is to say, future rewards are discounted such that they are worth subjectively less as a result of the delay. In intertemporal choices, participants often make choices between rewards which are smaller but sooner versus larger but longer ones. Then, the consequent problem is, to gain the maximum utility should one choose the long-term interests or the short-term interests? According to the perceived-time-based model, diminishing sensitivity to longer time horizons and the level of time contraction overall contribute to the degree of hyperbolic discounting. Therefore, the cognition and evaluation of time dimension is of high importance. This is called time perspective (TP). TP refers to the ways in which an individual views his/her past, present and future. It reflects personality difference in the dimension of time, and it is the relatively steady personality trait and behavioral characteristic expressed in an individual’s cognition, experience and actions (or action tendencies) for time. However, people lay diversely emphasis on the TP framework of past, present and future. With time perspective as the special characteristic of an individual, this paper is going to explore if there is difference in preference for intertemporal choice between different groups divided by TP and what it is. Hence, this study hypothesizes that the time perspective may have an important effect on intertemporal choice. With a classic paradigm of the DDT (delay-discounting-task), we tested the preferences for intertemporal choice between different groups divided by time perspective. A total of 40 persons (M age=21.6, SD=1.91), comprising 47.5% men and 52.5% women completed Zimbardo Time Perspective Inventory (ZTPI-25; Zimbardo & Bond, 2011) before they went to DDT. Only “Present hedonistic” (PH, enjoyment and pleasure seeking in the present), “Positive past” (PP, a warm and affectionate concept of past) and “Future” (F, planning and achievement of future goals) subscales were used. Based on the result of TP test, subjects were divided into two parts: future-time-oriented group and present hedonistic-oriented group。Then, all participants completed DDT, in which each one made a series of monetary choices between ￥d today or ￥d’ in 7 day (or 15day, 30day). They were asked to circle either ￥d today or ￥d’ in delayed day, where the percent difference in money amounts between the two rewards ((￥d’-￥d)/ ￥d) was selected from the set {5%, 10%, 15%, 25%, 35%, 50%, 70%, 95%}. Directly in line with our hypothesis, the results showed that compared to subjects of future time oriented, those of present hedonistic oriented preferred immediate but smaller rewards to delayed but larger rewards. In the contrary, those future-time-oriented subjects had relatively more incline for delay gratification. The specific findings were two aspects: 1) the delayed discounting rate of present hedonistic-oriented group was higher than that of future-time-oriented group; 2) the “Future” scores that future-time-oriented group had gained from the TP subscale were in negative correlation with their delayed discounting rate. In conclusion, the findings indicate that time perspective is an important individual trait that should be considered into affecting factors of intertemporal choice. Time perspective could influence individual preference for choices by changing the sensitivity of time horizons. As a stable personality characteristic, time perspective is able to predict well individual preference for intertemporal choice. The findings not only enrich the intertemporal choice theories, it also helps us further understand time perspective and perception, and suggests that we should weigh the time factor to make rational decisions.

Key words: intertemporal choice, time perspective, delay discounting

摘要： 利用津巴多时间洞察力问卷，采用跨期选择经典范式，考察“现在享乐型”和“未来定向型”两类时间洞察力个体在跨期选择上的偏好，从人格特质角度来探究跨期选择的认知机制。结果发现：(1)现在享乐定向组的延迟折扣率显著高于未来定向组；(2)未来定向组在时间洞察力量表“未来维度”得分与延迟折扣率显著负相关。这说明时间洞察力对个体延迟折扣率具有预测作用，支持了跨期选择的时间感知基础模型。

关键词: 跨期选择, 时间洞察力, 延迟折扣