1. Department of Linguistic and Cultural Evolution, Max Planck Institute for the Science of Human History, Jena 07745, Germany
2. ARC Centre of Excellence for the Dynamics of Language, ANU College of Asia and the Pacific, Australian National University, Canberra 2700, Australia
3. Religion Programme, University of Otago, Dunedin 9016, New Zealand
4. Centre for Research on Evolution, Belief and Behaviour, University of Otago, Dunedin 9016, New Zealand
5. Department of Biology, Washington University in St Louis, St Louis, MO 63130, USA
6. School of Psychology, University of Auckland, Auckland 1010, New Zealand
7. Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, ON, Canada M5S 3B2