If you want to understand changing social attitudes to marriage, looking at the people who've chosen to do it a second time while still legally married to their first spouse can provide a unique insight.
Mélanie Méthot, a professor of history at Canada's University of Alberta, has been researching bigamy "to better understand our idea of marriage, not only the legal definition, not only what the courts thought about it, but our religion or society," she said.
