  This manuscript explores the research topics and collaborative behaviour of
authors in the field of the Prisoner's Dilemma using topic modeling and a graph
theoretic analysis of the co-authorship network. The analysis identified five
research topics in the Prisoner's Dilemma which have been relevant over the
course of time. These are human subject research, biological studies,
strategies, evolutionary dynamics on networks and modeling problems as a
Prisoner's Dilemma game. Moreover, the results demonstrated the Prisoner's
Dilemma is a field of continued interest, and that it is a collaborative field
compared to other game theoretic fields. The co-authorship network suggests
that authors are focused on their communities and that not many connections
across the communities are made. The most central authors of the network are
the authors connected to the main cluster. Through examining the networks of
topics, it was uncovered that the main cluster is characterised by the
collaboration of authors in a single topic.
  These findings add to the bibliometrics study in another field and present
new questions and avenues of research to understand the reasons for the
measured behaviours.
