ogy aimed at explaining developmental change; that is, it deals with the search
for the origins and processes of change.

In this book, we focus on life-span developmental psychology, for
we are committed to advancing that particular emphasis and therefore prefer
to think and write in life-span terms. In fact, once in a while we allow
ourselves to believe that the life-span developmental view can be considered
at least the umbrella for any other more specialized developmental approach
and perhaps even the only appropriate developmental orientation.

In our judgment, the focus on life-span developmental psychology
has both costs and benefits. The theoretical and methodological benefits
derive from the fact that a life-span approach is apt to dramatize key
methodological issues of developmental research in an extreme and exem-
plary fashion--an effective feature from a didactic point of view. The major
theoretical cost of a life-span orientation is its current strong focus on age
development. We are, of course, aware that many developmentalists argue
that the goal of developmental research should be the identification of key
behavior-change processes rather than age changes and that they see the age
variable as transient and therefore unproductive for theory construction. We
will understand, therefore, if some readers wonder why much of our
discussion centers around age development rather than behavior-change
processes. We hope that such readers will be flexible enough to transfer our
methodological perspectives to their own research questions.

This book--we still don't really know why--was a very difficult one
for us to produce. If it were not for our sympathetic and supportive spouses
( Margret Baltes, Nancy Reese, and Carolyn Nesselroade), cooperative and
able editorial and secretarial helpers ( Sally Barber, Diane Bernd, Kathie F.
Droskinis, Barbara Gary, Margaret Swanson, and Ingrid Tarantelli), and
competent editorial assistants ( Steven Cornelius, Kathie F. Droskinis, Carol
Ryff, and Alison Okada Wollitzer), the book would probably still be in its
conception. We would also like to express our thanks to Nancy W. Denney,
of the University of Kansas, and K. Warner Schaie, of the Pennsylvania State
University, who provided many helpful comments and criticisms as editorial
consultants for the original publisher, to Freda Rebelsky and Lynn Dorman,
editors of the series in which this book originally appeared, and to the most
able editorial staff of Brooks/Cole, the publisher of the original volume. At
the same time, we are the ones responsible for any shortcomings that the
full-term book may have. You, the reader, will determine whether or not the
book will age gracefully.

Paul B. Baltes
Hayne W. Reese
John R. Nesselroade
November, 1987

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