We investigated whether great apes, like human infants, monkeys and dogs, are subject to a strong gravity bias when tested with the tubes task, and--in case of mastery--what the source of competence on the tubes task is. We presented 22 apes with three versions of the tubes task, in which an object is dropped down a tube connected to one of three…

Comments on an article by Rips et al. L. J. Rips, S. Blok, and G. Newman (2006) proposed that singular concepts, which support the tracing of individual objects across their existence, are governed by a principle of causal continuity. They purported to show that causal continuity is better than existing theories at explaining judgments of the…

Responds to comments made by Rhemtulla and Xu on the current authors' original paper Concepts of individual objects (e.g., a favorite chair or pet) include knowledge that allows people to identify these objects, sometimes after long stretches of time. In an earlier article, the authors set out experimental findings and mathematical modeling to…

This article considers how people judge the identity of objects (e.g., how people decide that a description of an object at one time, t-sub-0, belongs to the same object as a description of it at another time, t-sub-1). The authors propose a causal continuer model for these judgments, based on an earlier theory by Nozick (1981). According to this…