ABSTRACT
Among several key emergent trends in the study of development across the life span were
(a) the shift in emphasis from the two-occasion-based measurement of change to the
multioccasion focus on change functions and (b) the recognition and separation of
intraindividual variability and intraindividual change in the effort to represent concepts of
process more fruitfully (Hertzog & Nesselroade, 2003). Psychologists have long been
interested in the modeling of process, but the recent psychological literature shows
evidence of a more urgent, pervasive commitment to the task. Even in areas with a
long-standing tradition of emphasizing stability, for example, research on personality
traits, there is an awareness of the need for process-oriented accounts of the linkage
between traits and manifest behaviors (e.g., McCrae & Costa, 1996). On the one hand,
the emergence of these process-oriented sentiments is highly encouraging, but, on the
other, we do not believe that it will suffice. A close examination of the way research
questions are framed and the popular methods by which answers are sought does not
generate much optimism concerning an impending “great leap forward” in the study of
process.