A Coconstructionist View of the Third Age: The Case of Cognition1
Willis, Sherry L., Schaie, K. Warner, Annual Review of Gerontology & Geriatrics
In this chapter, we propose a coconstructionist model for the study of development within the Third Age using cognition as the sample case. In the first part of the chapter, we focus on the predecessors of cognitive development during the Third Age that occur in young adulthood and midlife. A coconstructionist view of cognition includes the identification of sets of neurobiologic and sociocultural influences whose role in affecting cognitive change during the Third Age will be considered. Two life span perspectives inform our model: The dual intelligence perspective proposed by Horn and Cattell (1967) and subsequently discussed by Baltes and colleagues, and second, the recent Coconstructionist perspective proposed by Baltes and colleagues (Baltes, 1997; Li, 2003; Li & Freund, 2005).
LIFE SPAN PERSPECTIVE OF DEVELOPMENT
A central task of life span psychology is to understand the interactive and dynamic nature of contextual and individual influences on development (Bakes, 1997; Li & Freund, 2005; Schaie, 2005). This dynamic interaction between individual and contextual influences leads to considerable variability in development-inter-individual differences in intra-individual change. Although inter-individual variability in intra-individual change is a tenet of the life span perspective, most cognitive aging studies have focused primarily on the normative pattern of cognitive change over a given age range.
Variability in intra-individual development becomes even more complex when studied over historical time, in identifying cohort differences in variability in intra-individual change. Given the challenges of examining cohort trends in intra-individual change, most research has been limited to a comparison of at most two cohorts at a single developmental period, such as the Third Age and on one or two cognitive domains. Moreover, these studies have focused on normative patterns of cohort differences in cognition and thus have not addressed variability in the pattern of individual differences in intra-individual change that would be expected to occur across cohorts. We also consider here how cognition in the Third Age has changed over historical time.
THE COCONSTRUCTIVE PERSPECTIVE
Both neurobiologie and sociocultural influences on development have long been recognized. Coevolutionary theorists (Dunham, 1991; Tomasello, 1999) maintain that both biologic and cultural evolution has occurred and that recent, cohort-related advances in human development in domains such as intelligence can be attributed largely to cumulative cultural evolution. Cultural activities impact the environment, thereby influencing mechanisms such as selection processes, and thus allowing humans to codirect their own evolution (Dunham, 1991). Baltes' coconstructionist approach imposes a life span developmental perspective on revolutionary theory and provides principles regarding the timing of the varying contributions of neurobiology and culture at different developmental periods and across different domains of functioning. Three principles are proposed regarding the relative contributions of biology and culture influences across the life span:
1. The beneficial effects of the evolutionary selection process occur primarily in early life and are less likely to optimize development in the latter half of life.
2. Further advances in human development depend on ever-increasing cultural resources. From a historical perspective, increases in cultural resources have occurred via cumulative cultural evolution and have resulted in humans reaching higher levels of functioning. At the individual level, increasing cultural resources are required at older ages for further development to occur or to prevent age-related losses. The implication then, for the Third Age, is that cultural resources become increasingly important.
3. In very old age, the efficacy of increasing cultural resources is diminished because decline in neurobiologic functions. …