The roots of this book go back to the 1960s, when I began to worry about how to make experimental psychology relevant to the problems of the world, especially through the improvement of education (Baron, 1971). The two most salient figures of my undergraduate days, Skinner and Bruner, had made me think that this was possible, and that real advances in educational technology could grow out of psychological theory. Bruner (1957) also gave me — perhaps even more than he intended — a view of what aspects of human thinking need to be corrected, namely, a rigidity resulting from first impressions.

During the political turmoil of the late sixties, my wife gave me an article by Lawrence Kohlberg, and his ideas seemed to provide much enlightenment about the conflicts of those years. I spent a few years trying to work on moral reasoning, in the tradition of Kohlberg. Much of this work was done in collaboration with John Gibbs while we were both at McMaster University. I became dissatisfied with Kohlberg's scoring methods (for reasons I explain here), and I gradually diverged from Gibbs and developed a system much along the lines of Chapter 3 here.

My interest in intelligence was inspired by my wife and by the late Klaus Riegel (in graduate school) and later by Block and Dworkin's (1976) excellent collection.