This report is based primarily on a survey of writings about the first five years of a child's development by persons who have received National Institute of Mental Health grants for investigations of this earliest period of life. An attempt has been made to sample the reports of these investigators, many of whom are prolific writers, and to render a fair representation of their contributions and thoughts. Although some work cited was not supported by NIMH, the overwhelming majority of the studies referenced herein were conducted with such grant assistance. Not all of any one man's work is covered; nor have all of the materials which were surveyed by us been used, so that the bibliography presented itself represents a selection from a larger body of writings reviewed.
The report is not simply a record or listing of major findings of the concerned investigators. Rather, it is an attempt to identify and correlate the ideas, themes, perspectives, and issues emerging from their studies which can be useful in the formulation and evaluation of social policies related to infant and child development in the present and future.
Given the fact that there are many schools of thought, many theoretical affinities, and many disparate ideological commitments among the investigators, the problem of providing cohesiveness as well as inclusiveness of the work of so many persons was a major difficulty. The studies did not fall into simple categories and classes on their own. Had we followed each writer in his own terms, with his commitments and theoretical biases, we would have mastered the element of inclusiveness, and faltered in respect to cohesiveness. Had we simply provided an account based upon a tightly knit perspective of our own, we would have achieved unity at the expense of many of the writers.
Accordingly, we have tried in the report to strike a balance between these tendencies. It has been necessary for us to reformulate many of the statements of investigators in order to achieve commonality with the statements of others. It also has been necessary to try to take a position in respect to the many topics that have been covered. Sometimes it has seemed to us that we have squeezed ideas from one viewpoint into that of another beyond what is likely to be preferred by the author, although we have never knowingly distorted the fundamental ideas of any author. At other times we have felt that we were too inclusive, that an idea we have inserted in one area is not definitively in that area, but fits there better than any place else. Given the task and the profound variability of interests and accomplishments, we see these weaknesses as inevitable and minor.
We have minimized certain areas of effort. We have not attended to the history, quality, validity, or other aspects of instruments for measuring cognitive and mental development. We permitted ourselves this exclusion because that task is itself a major one and would require as much effort or more than we have put into the present analysis. Furthermore . . .