Identity, influence, and change: rediscovering John Turner's vision for social psychology.

John Turner, whose pioneering work on social identity and self-categorization theories changed the face of modern social psychology, died in July 2011. This unique virtual special issue celebrates Turner's life and work by reproducing a number of key articles that were published in the British Journal of Social Psychology and the European Journal of Social Psychology over the course of his career. These articles are of three types: first, key position papers, on which Turner was the leading or sole author; second, papers that he published with collaborators (typically PhD students) that explored key theoretical propositions; third, short commentary papers, in which Turner engaged in debate around key issues within social psychology. Together, these papers map out a clear and compelling vision. This seeks to explain the distinctly social nature of the human mind by showing how all important forms of social behaviour - and in particular, the propensity for social influence and social change -are grounded in the sense of social identity that people derive from their group memberships. As we discuss in this editorial, Turner's great contribution was to formalize this understanding in terms of testable hypotheses and generative theory and then to work intensively but imaginatively with others to take this vision forward.