Pascual Ignacio, Aguirre Jacobo, Manrubia Susanna, Cuesta José A
Grupo Interdisciplinar de Sistemas Complejos (GISC), Madrid, Spain.
Departamento de Matemáticas, Universidad Carlos III de Madrid, Spain.
R Soc Open Sci. 2020 Feb 19;7(2):191813. doi: 10.1098/rsos.191813. eCollection 2020 Feb.
Every now and then the cultural paradigm of a society changes. While current models of cultural shifts usually require a major exogenous or endogenous change, we propose that the mechanism underlying many paradigm shifts may just be an emergent feature of the inherent congruence among different cultural traits. We implement this idea through a population dynamics model in which individuals are defined by a vector of cultural traits that changes mainly through cultural contagion, biased by a 'cultural fitness' landscape, between contemporary individuals. Cultural traits reinforce or hinder each other (through a form of cultural epistasis) to prevent cognitive dissonance. Our main result is that abrupt paradigm shifts occur, in response to weak changes in the landscape, only in the presence of epistasis between cultural traits, and regardless of whether horizontal transmission is biased by homophily. A relevant consequence of this dynamics is the irreversible nature of paradigm shifts: the old paradigm cannot be restored even if the external changes are undone. Our model puts the phenomenon of paradigm shifts in cultural evolution in the same category as catastrophic shifts in ecology or phase transitions in physics, where minute causes lead to major collective changes.
社会的文化范式不时会发生变化。虽然当前文化变迁的模式通常需要重大的外部或内部变革，但我们认为，许多范式转变背后的机制可能仅仅是不同文化特征之间内在一致性的一种涌现特征。我们通过一个种群动态模型来实现这一想法，在该模型中，个体由一组文化特征向量定义，这些特征主要通过文化传播而变化，在当代个体之间受到“文化适应性”景观的影响。文化特征相互强化或相互阻碍（通过一种文化上位性形式）以防止认知失调。我们的主要结果是，只有在文化特征之间存在上位性的情况下，并且无论水平传播是否受到同质性的影响，才会因景观的微弱变化而发生突然的范式转变。这种动态变化的一个相关结果是范式转变的不可逆性：即使外部变化被消除，旧范式也无法恢复。我们的模型将文化进化中的范式转变现象与生态学中的灾难性转变或物理学中的相变归为同一类，即微小的原因会导致重大的集体变化。
