Great apes anticipate that other individuals will act according to false beliefs

Abstract

( fig. S20), the mechanical properties of the synthetic nacre are still not as good as that of natural nacre (35,36) (Fig. 4, B and C). Due to the larger aspect ratio of the aragonite platelets in the synthetic nacre, the platelets exhibit a "partly pullout" behavior, which leads to lower crack-resistance capability.Because the precipitation of the second phase onto the matrix relies on electrostatic force, CaCO 3 and chitin can be substituted by other precursors with opposite charges to make superior composites such as engineering ceramics (21-24) (figs. S21 and S22). Besides, as the dependence of properties of the composite materials on the characteristic length of their periodic microstructure (37), the mechanical performance of these materials can be optimized by adjusting the properties of the original matrix (38), which affect both the amount of electrostatically absorbed precipitates and the density of the nucleation sites. The fabrication of the laminated synthetic nacre is not a special case; there are other techniques, such as programmable 3D printing, for constructing predesigned macroscopic matrices that can be readily incorporated with our strategy to produce composite materials. Moreover, this strategy is also adaptable for fabricating robust bulk materials with brittle and heat-labile components ( fig. S21B). Given the importance of nano-and microscopic structures for the materials performance, we thus anticipate that our method can be extended to produce various composite materials with unique properties. Humans operate with a "theory of mind" with which they are able to understand that others' actions are driven not by reality but by beliefs about reality, even when those beliefs are false. Although great apes share with humans many social-cognitive skills, they have repeatedly failed experimental tests of such false-belief understanding. We use an anticipatory looking test (originally developed for human infants) to show that three species of great apes reliably look in anticipation of an agent acting on a location where he falsely believes an object to be, even though the apes themselves know that the object is no longer there. Our results suggest that great apes also operate, at least on an implicit level, with an understanding of false beliefs.C entral to everything that makes us humanincluding our distinctive modes of communication, cooperation, and culture-is our theory of mind (TOM). TOM is the ability to impute unobservable mental states, such as desires and beliefs, to others (1, 2). For nearly four decades, a cardinal question in psychology has concerned whether nonhuman animals, such as great apes, also possess this cognitive skill (1, 3). A variety of nonverbal behavioral experiments have provided converging evidence that apes can predict others' behavior, not simply based on external cues but rather on an understanding of others' goals, perception, and knowledge (3, 4). However, it remains unclear whether apes can comprehend reality-incongruent mental states (e.g., false beliefs) (3...

Empirical approaches to the study of language evolution

“…However, a series of recent experiments with chimpanzees shows that at least a basic capacity to represent the knowledge of others is present in apes (Bräuer, Call, & Tomasello, 2007;Call & Tomasello, 2008;Hare et al, 2000), and very recent data based on eyetracking suggests a capacity to represent false beliefs as well (Krupenye et al, 2016). These results indicate that a capacity for first-order ToM was already present in the LCAc.…”

The Developmental Origins of False-Belief Understanding

“…False-belief understanding requires the ability to recognize that mental states are internal representations rather than direct reflections of reality and thus can be inaccurate. This ability may be uniquely human (e.g., Kaminski, Call, & Tomasello, 2008, but see Krupenye, Kano, Hirata, Call, & Tomasello, 2016) and has been argued to play an important role in many human social behaviors (e.g., Herrmann, Call, Hernández-Lloreda, Hare, & Tomasello, 2007). For instance, recognizing that others' representations of the world may differ from our own helps us communicate more effectively and facilitates cooperation (e.g., Baillargeon et al, 2013).…”

Submentalizing Cannot Explain Belief-Based Action Anticipation in Apes

“…An enduring question in cognitive science concerns the extent to which this theory of mind (ToM) is shared with nonhuman animals [1]. Adapting a seminal eye-tracking paradigm [2], we recently showed that humans' closest ape relatives (bonobos, chimpanzees, and orangutans) can pass a modified false belief test [3]. Specifically, apes looked in anticipation of an actor searching for an object where the actor had last seen it, even though the apes themselves knew that it was no longer there.…”