Development of Intellectual Abilities in Old Age: From Age Gradients to Individuals

Abstract

According to two-component theories, intellectual development across the lifespan is based on dynamic interactions between biology-driven fluid abilities (broad Gf, or the mechanics of cognition) and culture-driven crystallized abilities (broad Gc, or the pragmatics of cognition).In this chapter, we advocate a stronger reliance on intra-individual patterns and changes to overcome some of the conceptual and methodological problems associated with the investigation of interactions between the mechanics and the pragmatics in adulthood and old age. First, evidence about cross-sectional and longitudinal gradients of the pragmatics and mechanics during adulthood and old age is summarized. Second, we note that an improved understanding of these gradients requires efforts to decompose time/age into constituent components such as senescence, retest effects, terminal decline, cohort differences, and selective attrition. Third, the dedifferentiation hypothesis of intelligence in old age is framed in terms of mechanics/pragmatics interactions, and recent attempts to directly model these interactions using advanced structural equation modeling techniques are described. Fourth, we argue that the study of interindividual differences in a developmental context is often used to investigate substantive hypotheses that are ultimately located at the level of intraindividual patterns of changes. Therefore, interindividual-difference methods need to be complemented by the study of intraindividual variability, patterns, and changes. Intraindividual data would enable researchers to assess the amount and correlates of sample heterogeneity in patterns of performance and change, and to gauge the validity of interindividual-difference methods. The chapter ends with a discussion of methods for the study of intraindividual patterns of change. 3The present chapter has two main objectives: (a) to summarize psychometric theorizing and evidence about intelligence in adulthood and old age, and (b) to promote a person-centered (idiographic) approach to the psychometric study of adult intellectual development. Both objectives can be framed in the context of two-component models of lifespan cognition. These models posit that lifespan development of intellectual abilities reflects two fundamental and dynamically interacting influences, the biological and the cultural. Historical examples of such models can be found in Tetens' (1777) differentiation between relative and absolute mental capabilities and in Hebb's (1949) distinction between intellectual power and intellectual products (Hebb, 1949). Typical contemporary examples include the theory of fluid and crystallized intelligence (i.e., Gf-Gc theory;Cattell, 1971;Horn, 1982;Horn & Cattell, 1966, 1967, the PPIK theory (Ackerman, 1996), and the decomposition of cognition into the mechanics and the pragmatics (Baltes, 1987;Baltes, Lindenberger, & Staudinger, 1998). Though the scope, terminology, and details vary considerably across the different versions, they all share fundamental assumpti...

Social Participation Attenuates Decline in Perceptual Speed in Old and Very Old Age.

“…Baltes, Lindenberger, & Staudinger, in press;Li, 2003;Lövdén & Lindenberger, 2005). Both conceptually and methodologically, it is therefore important to consider the time scale on which interactions between engaged lifestyle and cognitive functioning may be operating.…”

Studying Individual Aging in an Interindividual Context: Typical Paths of Age-Related, Dementia-Related, and Mortality-Related Cognitive Development in Old Age.

“…In other words, when it comes to studying cognitive aging, we generally prefer to give interpretational priority to individuals' patterns of cognitive functioning over chronological age. In doing so we echo classic calls for replacing chronological age with variables closer to the developmental process of interest (Wohlwill, 1970; see also Lövdén & Lindenberger, 2005;S.-C. Li & Schmiedek, 2002;Sliwinski, Hofer, Hall, Buschke, & Lipton, 2003). The spirit of dynamic systems theories (e.g., Ford & Lerner, 1992;Gottlieb, 1992;Wohlwill, 1973) inherent in the LICUR procedure, reflected by allowing the cross-sectional cognitive profiles to determine both future cognitive states and developmental paths, offers a viable methodological basis for such endeavors.…”

“…However, to better understand cognitive aging, it may be necessary to investigate its antecedents at the level of the individual and to allow for interindividual variability in the importance of different biological and sociocultural mechanisms (cf. Lövdén & Lindenberger, 2005).…”

“…An individual-oriented approach to the study of development is not new; on the contrary, key characteristics of this approach have been delineated by proponents of a person-oriented perspective (e.g., Allport, 1937;Bergman, Magnusson, & El-Khouri, 2003;Block, 1971;Magnusson, 2001), life span developmental theoreticians and methodologists (e.g., Baltes & Nesselroade, 1979;Baltes, Reese, & Nesselroade, 1977; see also Hertzog, 1985;Lövdén & Lindenberger, 2005;Molenaar, Huizenga, & Nesselroade, 2003), and developmental systems theoreticians (e.g., Ford & Lerner, 1992;Gottlieb, 1992;Wohlwill, 1973; see also S.-C. Li, 2003). Broadly viewed, four related perspectives guide the individual-oriented agenda.…”

“…As noted above, several recent studies have also suggested that the multivariate cognitive pattern of change in the terminal decline phase may differ from age-related changes. Specifically, the terminal decline phase may be characterized by a pattern of global cognitive change, including decline in crystallized abilities such as semantic memory, which may be relatively unaffected by aging-related processes (e.g., Singer et al, 2003;Small et al, 2003; see also Lövdén & Lindenberger, 2005). Therefore, a final empirical objective was to provide further knowledge concerning the multivariate patterns of change in terminal decline.…”