Intuition, Reflection & Communication In the Building of Human Cultures Nicolas Baumard1 & Pascal Boyer2 Abstract. In recent years, a naturalist understanding of human cultures has proposed to explain human culture with the help of disciplines such as evolutionary biology, cogni-tive psychology, behavioral economics and cultural modelling. Despite impressive re-sults, this naturalist program has only had a limited impact on the various social sci-ences, on cultural anthropology in particular. Indeed, the naturalist programme does not seem to say much about what anthropologists usually work on. It puts forward theories of zoological folk-taxonomies but not of animal mythologies; of parental in-vestment but not of lineage systems; of musical forms but not of artistic ideologies; of everyday actions but not of rituals; of people's botany but not of magic; of cooperation but not of people's moral imperatives. Here, we propose that a synthetic account of cultural knowledge is possible within the framework of an evolution-based, cognitive account of cultural transmission. This requires that we pay particular attention to the distinction between intuitive beliefs and reflective beliefs, a distinction that is of crucial importance for the acquisition and transmission of cultural knowledge. Specially so, as most naturalist approaches have focused on intuitive beliefs so far, while most of the “thick” cultural material of anthropology consists of reflective beliefs. 1. Cultural knowledge and the naturalist program The naturalistic approach has allowed anthropologists and psychologists to combine findings and models from evolutionary biology, experimental psy-chology, behavioural economics and cultural anthropology (Tooby and Cosmides 1992; Sperber 1996; Richerson and Boyd 2005). In this framework, it has proved possible to put forward specific, testable models of cultural know-ledge in such domains as folk-biology (Atran 1993, 1998), language (Evans and Levinson 2009), music (Patel 2010), numbers (Gallistel and Gelman 2000), coalitions (Kurzban and Leary 2001), kinship and ethnic categories (Hirschfeld 1994, 1996), racial categories (Kurzban, Tooby, and Cosmides 2001), religious beliefs (Boyer 1992; Pyysiainen 2001), morality (Haidt 2007) 1 University of Oxford and Institut Jean Nicod, Paris 2 Washington University in St. LouisIntuitions, Reflections and Communication 2 and social exchange (Cosmides and Tooby 2005; Fiske 1992), among others. Also, formal quantitative models inspired by population genetics have been put forward to provide precise models of the diffusion of norms, concepts or behaviors (Richerson and Boyd 2005; Sperber and Claidière 2006). Despite impressive results, this naturalist program has only had a limited impact on the various social sciences, on cultural anthropology in particular. Indeed, a common reaction from social scientists, especially anthropologists, is that however interesting in principle the programme does not address issues they usually work on (Lloyd 2007; Descola 2009). The naturalist programme does not seem to say much about cultural symbolism, for lack of a better term. So we have studies of zoological folk-taxonomies but not of animal mytholo-gies; of parental investment but not of lineage systems; of musical forms but not of artistic ideologies; of everyday actions but not of rituals; of people's botany but not of magic; of cooperation but not of people's moral imperatives. Conversely, it is clear that current cultural anthropology does not provide a coherent answer to fundamental questions of cultural transmission (Boyd and Richerson 1996; Sperber 1996), viz., Why do we find similarities in different cultural traditions? Why do cultural concepts and norms remain stable across generations? What explains success and failure in cultural transmission?. In the last thirty years or so, many cultural anthropologists have actually abandoned these general questions and more generally segregated their research programs from related scientific disciplines such as economics, biology, psychology and the neurosciences (D'Andrade 1995). Surprisingly, this happened at the very time these disciplines made great progress while a large readership manifested a great interest in an integrated understanding of human nature (Boyer 2011). These developments resulted in a division of labor in which various sci-ences account for the capacities that make cultures possible (but rarely consider the similarities and diversity in the result), while anthropologists consider the results but cannot integrate them into any scientific explanation. We propose that a synthetic account of cultural knowledge is possible within the framework of an evolution-based, cognitive account of cultural transmission. This requires that we pay particular attention to the distinction between intuitive beliefs and reflective beliefs, a distinction that is of crucial im-portance for the acquisition and transmission of cultural knowledge. Specially so, as most naturalist approaches have focused on intuitive beliefs so far, whileIntuitions, Reflections and Communication 3 most of the “thick” cultural material of anthropology consists of reflective be-liefs. Here, we delineate three logical steps in the creation of roughly shared men-tal representations in human groups. [1] Human minds comprise a large num-ber of highly specialized cognitive systems that produce intuitive beliefs about a range of situations of evolutionary import. [2] Human minds also produce a large number of spontaneous, highly variable reflective beliefs that complement, compare and evaluate their intuitive beliefs. [3] Communication results in the selection of a small subset of these reflective beliefs that become widespread within a social group. We illustrate these points with empirical evidence con-cerning folk-medicine, moral prescriptions, social categorization and theories of the person. The framework suggests an integrated view of human cultures that connects scientific knowledge about human evolution and cognition to a renewed understanding of classical anthropological issues. 2. Creating cultures, Step 1: Intuitive systems 2.1. Evolved domain-specific intuitive systems Evolutionary biology and cognitive