- Correspondence to Dr Alex Gillespie, Department of Social Psychology, London School of Economics, London WC2A 2AE, UK;
- Received 13 July 2015
- Revised 22 October 2015
- Accepted 25 October 2015
- Published in print 1 December 2016.
- Published online 18 November 2016.
- Published first 6 January 2016.
This web only file has been produced by the BMJ Publishing Group from an electronic file supplied by the author(s) and has not been edited for content.
- Data supplement 1 - Online supplement
If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.