The roots of many current models of the development of schizophrenia can be traced to the theory advanced by Meehl in 1962. In this symposium volume, dedicated to Philip Holzman – whose own work and insights have illuminated our present understanding of schizophrenia so greatly and who attributes his turning toward research in that disorder to his reading the 1962 paper (Holzman, 1990) – it seems especially fitting, therefore, to begin my reflections on some of the features of contemporary developmental models with a look back at their most influential source, Meehl's original model. This is not to say that his model is not still up-to-date and important. Meehl (1989, 1990) has continued to update it and to make alterations as appropriate, based on new information. My task here, though, is to point out some of the conceptual changes and additions that have evolved in thinking about modelling schizophrenia's development, in light of accumulating research findings over the past two or three decades.

Summary of Meehl's model

Only a brief reminder about the essential elements of Meehl's model is in order here, as the theory, with its causal chains leading to the symptoms of schizophrenia, has been summarized many times (e.g., Gottesman and Shields, 1972, 1982; Meehl, 1972a, 1972b, 1989, 1990; Gottesman, 1991).