Department of Anthropology and Center for Behavior, Evolution, and Culture, University of California, Los Angeles, Los Angeles, California, United States of America.
Department of Anthropology, University of California, Santa Barbara, Santa Barbara, California, United States of America.
PLoS One. 2014 Apr 15;9(4):e95167. doi: 10.1371/journal.pone.0095167. eCollection 2014.
The functions of cultural beliefs are often opaque to those who hold them. Accordingly, to benefit from cultural evolution's ability to solve complex adaptive problems, learners must be credulous. However, credulity entails costs, including susceptibility to exploitation, and effort wasted due to false beliefs. One determinant of the optimal level of credulity is the ratio between the costs of two types of errors: erroneous incredulity (failing to believe information that is true) and erroneous credulity (believing information that is false). This ratio can be expected to be asymmetric when information concerns hazards, as the costs of erroneous incredulity will, on average, exceed the costs of erroneous credulity; no equivalent asymmetry characterizes information concerning benefits. Natural selection can therefore be expected to have crafted learners' minds so as to be more credulous toward information concerning hazards. This negatively-biased credulity extends general negativity bias, the adaptive tendency for negative events to be more salient than positive events. Together, these biases constitute attractors that should shape cultural evolution via the aggregated effects of learners' differential retention and transmission of information. In two studies in the U.S., we demonstrate the existence of negatively-biased credulity, and show that it is most pronounced in those who believe the world to be dangerous, individuals who may constitute important nodes in cultural transmission networks. We then document the predicted imbalance in cultural content using a sample of urban legends collected from the Internet and a sample of supernatural beliefs obtained from ethnographies of a representative collection of the world's cultures, showing that beliefs about hazards predominate in both.
文化信仰的功能对信仰者来说往往是不透明的。因此，为了从文化进化解决复杂适应问题的能力中获益，学习者必须轻信。然而，轻信会带来成本，包括易受剥削和因错误信念而浪费的努力。轻信的最佳水平的一个决定因素是两种错误成本之间的比率：错误的轻信（未能相信真实的信息）和错误的轻信（相信虚假的信息）。当信息涉及危险时，这种比率可以预期是不对称的，因为错误的轻信的成本平均会超过错误的轻信的成本；没有类似的不对称性可以描述与利益有关的信息。因此，自然选择可以预期已经塑造了学习者的思维，使其对涉及危险的信息更加轻信。这种负偏向的轻信扩展了一般的负性偏差，即负面事件比正面事件更突出的适应性倾向。这些偏见共同构成了吸引子，通过学习者对信息的差异保留和传播的累积效应，应该影响文化进化。在两项美国研究中，我们证明了负向轻信的存在，并表明它在那些认为世界危险的人中最为明显，这些人可能是文化传播网络中的重要节点。然后，我们使用从互联网上收集的都市传说样本和从世界文化代表集合的民族志中获得的超自然信仰样本记录了文化内容的预期不平衡，表明两种信仰都占主导地位。
