1. Centre for Behaviour and Evolution, School of English Language, Literature and Linguistics, Newcastle University, NE1 7RU UK
2. Centre for Language Evolution, University of Edinburgh, 3 Charles St, Edinburgh, EH8 9AD, UK
3. Department of Anthropology and Archaeology, University of Bristol, 43 Woodland Road, Bristol, BS8 1UU, UK
4. Department of Chinese and Bilingual Studies, The Hong Kong Polytechnic University, 11號 Yuk Choi Rd, Hong Kong
5. Leiden Institute of Advanced Computer Science, Universiteit Leiden, Niels Bohrweg 1, 2333 CA Leiden, Netherlands