因果延续理论(Causal Continuer Theory)认为，人们对客体的同一性认识是由其知觉到的因果线索决定的。而单一概念理论(Singular Concept Theory)则认为人们对客体的同一性认识受到相似性、心理分类和客体的时空连续性影响。当组成客体的物质发生一定变化时，这两种理论在预测人们对客体的同一性认识上存在矛盾。本研究通过两个研究（共3个实验），采用双重转换机器(Dual-ing Machines)范式，操纵时空连续性线索和因果线索，考察两种理论在解释客体同一性认识中的作用。

研究一中的实验1以316名大学生为被试，操纵时空连续性线索（连续/不连续）与因果线索（强/弱），探讨它们是否影响被试在双重转换机器范式中对机器零件的客体同一性认识。结果发现：时空连续性线索和因果线索的主效应及其交互作用均不显著，但是在不同情境下被试均认为若零件发生变化则其客体同一性发生变化，这提示被试对客体同一性的认识依赖于因果线索。实验2以289名大学生为被试，排除了文本描述和提问方式的混淆影响，得到了与实验1一致的结果。

为了检验研究一的发现在不同情境中是否具有一致性，研究二操纵客体类型（生命、非生命、机器人）与物质来源占比（从0到100%），以149名大学生为被试，采用相同的双重转换机器范式，考察被试在判断不同类型客体的客体同一性时使用因果线索的差异。结果发现：相比于生命体和机器人，被试在判断非生命体的客体同一性时，更多地依赖于物质组成，即研究一的发现在非生命客体中更适用。

总的来说，本研究结果表明，在进行客体同一性追踪和判断时，人们会优先利用因果线索，支持了因果延续理论；而单一概念理论的适用性有待未来研究进一步探索。

The Causal Continuer Theory holds that people's understanding of object identity is determined by the Causal clues they perceive, whereas Singular Concept Theory holds that recognition of object identity is influenced by similarity, psychosortalism and spatiotemporal continuity of objects. When materials of the object changes, the two theories are contradictory in predicting the object identity. In the two studies (3 experiments in total) of current research, the Dual-ing Machines paradigm was used to manipulate spatiotemporal continuity clues and causal clues to investigate the role of the two theories in the interpretation for recognition of object identity.

In experiment 1 of study 1, 316 college students participated the experiment. By manipulating spatiotemporal continuity clues (continuous/discontinuous) and causal clues (strong/weak), experiment 1 explored whether the two clues affect the subjects' recognition of object identity under the situation of Dual-ing Machine Paradigm. The results show that the main effects and the interaction between the temporal and spatial continuity clues and causal clues are nonsignificant, but all the subjects thought that the object identity changes if the parts change, which indicates that the subjects' recognition of object identity depends on the causal clues. In experiment 2, 289 college students participated the experiment, in which the confounding influence of text description and question method have been eliminated. And experiment 2 obtained the consistent results with experiment 1.

To examine whether the conclusion obtained in study 1 is consistent in different situations, study 2 explored the differences in using causal clues to judge different type of objects, by manipulating the object types (life, inanimate, robot) and material sources accounted for (from 0 to 100%), with 149 college students as subjects, using the same Dual-ing Machine paradigm. The results showed that compared with animate and robots, subjects rely more on material composition when judging the identity of inanimate objects, which indicates that the findings of study I were more applicable in inanimate objects.

In general, the results of the current study show that causal clues are prior clues in tracing and judge object identity, which supports Causal Continuer Theory. The applicability of Singular Concept Theory needs to be further explored in the future.