He studies social behaviour in organizations, and evolution of cultures, with the perspective of an evolutionary biologist. He also acts as a speaker and invited lecturer around the world. Gert Jan creates and animates group simulation games with ambiguous incentive systems that allow natural group behaviours to occur in areas such as leadership, negotiation, and trust. He also works on agent-based modelling of ‘Homo biologicus’, including emotions and culture. The book Cultures and Organizations (3rd ed 2010) which he co-authored is a world-wide bestseller.