Smith, J., & Baltes, P. B. (1999). Trends and profiles of psychological functioning in very old age. In P. B. Baltes & K. U. Mayer (Eds.), The Berlin Aging Study: Aging from 70 to 100 (pp. 197-226). Cambridge: Cambridge University Press.
This chapter describes the
psychological and psychosocial status of the participants of the Berlin Aging
Study (BASE). In the first section, we outline age trends in three domains:
intelligence, self and personality, and social relationships. In the domain of
intelligence, negative age differences between 70 and 103 years were substantial
(representing a 1.8 SD difference in performance level and 35% of the
interindividual variance) and were closely associated with indicators of
biological deterioration. In contrast, age-related differences in personality,
self-related beliefs, and social relationships were fewer and considerably
smaller (approximately 0.5 SD). At a general level, these domains seemed to be
less affected by age-related decline than is true for intellectual functioning.
Closer examination, however, revealed that age differences on aspects of self,
personality, and social relationships were all in a less-than-desirable
direction. In advanced old age, individuals may be pushed to the limits of
their adaptive psychological capacity.
A further question considered in the chapter concerns the overall systemic nature of psychological functioning in old age. Cluster analysis was used to identify nine subgroups of older individuals with different patterns of functioning across the three psychological domains. Four of these groups reflected various patterns of desirable functioning (47% of the sample) and five, less desirable functioning (53%). The relative risk of membership in the less desirable profile subgroups was 2.5 times larger for the very old (85-103 years) than for people between the ages of 70 and 84 years, and 1.3 times larger for women compared to men. On this level of systemic-wholistic analysis, and compared to single-variable analyses, the very old appear to be a distinct group psychologically. This finding is consistent with recent predictions about a "fourth age" based on a theoretical analysis of the biological-genetic and sociocultural architecture of life-span development (P. B. Baltes, 1997).