Original Article The cultural morphospace of ritual form ☆ Examining modes of religiosity cross-culturally Quentin D. Atkinson a,c, ⁎ , Harvey Whitehouse b a Institute of Cognitive and Evolutionary Anthropology, University of Oxford, Oxford, United Kingdom b Centre for Anthropology and Mind, University of Oxford, Oxford, United Kingdom c Department of Psychology, University of Auckland, Auckland, New Zealand Initial receipt 8 February 2010; final revision received 9 September 2010 Abstract Ethnographic, historical, archaeological and experimental work suggests the existence of two basic clusters of ritual dynamics or ‘modes of religiosity’— a low-frequency, high-arousal cluster linked to the formation of small cohesive communities (imagistic mode) and high- frequency, low-arousal cluster associated with larger, more centralized social morphology (doctrinal mode). Currently, however, we lack a large-scale survey of ritual variation on which to test such predictions. Here, we compile data on 645 religious rituals from 74 cultures around the globe, extracted from the Human Relations Area Files, revealing that the cultural morphospace of ritual form favours rituals that are indeed either low-frequency and highly dysphorically arousing or high-frequency with lower arousal and that these ritual dynamics are linked to group size and structure. These data also suggest that low dysphoric arousal, high-frequency rituals may have been tied to the advent of agriculture and subsequent emergence of the first large-scale civilizations. © 2011 Elsevier Inc. All rights reserved. Keywords: Cultural evolution; Ritual; Religion; Agriculture; Modes of religiosity; Costly signalling; Human Relations Area Files 1. Introduction Religious rituals show an enormous diversity of form and function across the globe, but this diversity is not unbounded. Various clusters of ritual features are hypothe- sized to co-occur cross-culturally as a result of both cognitive constraints on the range of possibilities and functional constraints on how features interact with each other and the broader social system. For example, different elements of ritual form have been associated with costly signalling (Irons, 1996; Sosis & Alcorta, 2003; Sosis, Kress & Boster, 2007), obsessive compulsive disorder and the human hazard precaution system (Boyer & Lienard, 2006), cognitive constraints on memory systems (Whitehouse, 1992), the role ascribed to supernatural agency (McCauley & Lawson, 2002), modes of codification and transmission (Barth 1987; Turner 1974; Whitehouse 1995), and the scale and structure of religious communities (Gellner, 1969; Goody, 1986; Werbner 1977, 1989; Whitehouse 2000). To develop an understanding of the cultural evolution of religious rituals, these theories need to be tested in the light of evidence from a range of disciplines, including developmental and social psychology, cognitive neuroscience, behavioural economics and anthropology. Central to this project is the characterisation of cultural variation itself. With few exceptions, (e.g., Sosis et al. 2007), the above theories tend to be derived from ethnographic, archaeological or historical case studies and field work, and are therefore vulnerable to the charge of cherry-picking: that is, focussing on bodies of evidence and experimental designs likely to confirm the theory. To avoid this criticism, a large- scale global database of ritual variation is needed. By systematically cataloguing cross-cultural variation in the dimensions of interest, hypotheses can be tested statistically and the cherry-picking criticism overcome. Such an Evolution and Human Behavior 32 (2011) 50 – 62 ☆ This work was supported by the EC-FP6 EXREL project grant 43225 and a grant to Q.A. from the John Templeton Foundation-funded Cognition, Religion and Theology Project at Oxford University. ⁎ Corresponding author. Department of Psychology, University of Auckland, Private Bag 92019, Auckland 1142, New Zealand. Tel.: +64(0) 9373 7599x84316. E-mail address: q.atkinson@auckland.ac.nz (Q.D. Atkinson). 1090-5138/$ – see front matter © 2011 Elsevier Inc. All rights reserved. doi:10.1016/j.evolhumbehav.2010.09.002