In this concluding chapter, we note the special opportunities and the special hazards afforded by the emergence of a unified developmental science. We offer some comments on its past, take stock of its present, and speculate about its future.

Scope of Developmental Science

Judging from the review volumes that have been published in the 1990s, there are at least five domains of behavioral investigation that may be subsumed under the rubric developmental science. These loosely connected domains include the development of human personality and social actions, the ontogeny and evolution of the behavioral adaptations in nonhuman animals, the development of perception, movement, and language in infants and young children, the development of psychopathology and emotional disorders, and the development of cognitive processes in children and older adults.

These domains not only frame problems in different ways; they deal with different problems. Even when it appears that the issues are similar on formal grounds, there seems to be scant overlap in research designs and analytic strategies. Links have historically been made across developmental domains only at the highest levels of abstraction. One of the aims in this volume has been to articulate a framework that promotes more direct coordination and evaluation of developmental methods and concepts.

History provides clues to how a common frame can be achieved despite such divisions and the biases they represent. It seems altogether fitting that the present volume is published on the centennial of James Mark Baldwin's Mental Development in the Child and the Race (1895).