Science depends on noticing that things which seem identical are different, and conversely. In psychology, one cannot assume that apparently identical behaviours are due to identical mechanisms. The work reported in this book involves the problem of classifying the true nature of behaviour as it appears during child development. Originally published in 1982, the papers in this volume attempt to interpret, explain, or explain away developmental regressions in a variety of different areas. In spring 1975, a group of scholars interested in such problems met for several days to discuss their individual findings and the underlying theoretical issues. This volume reflects both the discussions at the original conference and succeeding years of thinking, reading and writing.
