Background
The 2nd International Conference on Thinking was held at the University of Plymouth, UK, in 1992, organized by Jonathan Evans. As part of the conference, a symposium was held on July 29 to honor Peter Wason, the originator of a number of extremely intriguing laboratory tasks widely used to investigate reasoning and hypothesis testing (most notable, the Wason selection task and the 2-4-6 task). He had recently retired. This photo was taken as Wason (who walked with difficulty) took his seat on the podium to deliver his concluding remarks, in which he discussed the origins of the tasks he had invented. Left to right: Phil Johnson-Laird, Peter Wason, Jonathan Evans. Photo courtesy of Jonathan Evans. Peter Wason passed away in 2003.
–Keith Holyoak