Broadly, Marc is interested in the application of social psychological theory to important social issues. Much of this research revolves around the relationship between the concepts of Social Dominance Orientation, authoritarianism, and social values, and such issues as the Treaty settlement process, New Zealand national identity, and political preference. He is also interested in social psychological factors influencing peoples' food preferences (eg. to eat or not eat meat), the psychology of religion, and people's beliefs about paranormal and conspiratorial phenomena. Marc’s main research programme, since 2012, has focused on understanding why some people (particularly young people) deliberately hurt themselves, without suicidal intent. This research has been supported by the Health Research Council of New Zealand and the Marsden Fund, under the umbrella of the Youth Wellbeing Study.

Marc has received both VUW (2005) and National (2008) Teaching Excellence Awards, and his science communication endeavours have been recognised by the New Zealand Association of Scientists Science Communicator Award (2010) and VUW’s Public Contribution Award (2011). He also writes a weekly psychology column in the New Zealand Listener.