Marc Lewis is a neuroscientist and a recently retired professor of developmental psychology – he was at the University of Toronto from 1989 to 2010, and at Radboud University in the Netherlands from 2010 to 2016. His latest book is The Biology of Desire (2015). He lives in the Netherlands.
Shaun Shelly is affiliated with the Department of Family Medicine at the University of Pretoria where he is a researcher and lecturer. Shaun started South Africa’s first harm-reduction centre, and currently heads the drug policy and rights programme at a national NGO. He is also on a number of local and international advisory boards. He lives in Cape Town, South Africa.