Tannis Y. Arbuckle

Structural equation model of intellectual change and continuity and predictors of intelligence in older men

This study examined the effects of abilities as a young adult, an engaged lifestyle, personality, age, and health on continuity and change in intellectual abilities from early to late adulthood. A battery of measures, including a verbal and nonverbal intelligence test, was given to 326 Canadian army veterans. Archival data provided World War Two enlistment scores on the same intelligence test for this sample: Results indicated relative stability of intellectual scores across 40 years, with increases in vocabulary and decreases in arithmetic, verbal analogies, and nonverbal skills. Young adult intelligence was the most important determinant of older adult performance. Predictors for verbal intelligence were consistent with an engagement model of intellectual maintenance but also indicated the importance of introversion-extraversion and age. Nonverbal intelligence in late life was predicted by young adult nonverbal scores, age, health, and introversion-extraversion.

Individual Differences in Trajectory of Intellectual Development Over 45 Years of Adulthood

The hypothesis that individual differences in adult intellectual development reflect variation in life context and personality was examined in 132 World War II (WWII) veterans. Intelligence data from the Canadian Army M Test were available for 3 occasions, WWII, 1984-1986 (Int85), and 1989-1991 (Int90). Performance declined over the 45 years on 5 subtests but improved on the 6th, Vocabulary. Correlations between WWII and Int90 scores showed considerable stability of individual differences in intelligence over 45 years. Younger age predicted less decline over 45 years on all subtests; a more engaged lifestyle predicted less decline on most subtests, and better health and greater introversion predicted less decline on some subtests. Predictors of change since Int85 were similar to those for the whole period. Implications for theories of adult intellectual development are discussed.

Social behavior and off-target verbosity in elderly people.

This study investigated social behavior in older adults with varying levels of off-target verbosity (OTV). After screening 455 adults in Phase 1, 198 individuals were selected to participate in both a get-acquainted conversation and an experimental cues situation and to complete social and cognitive measures. Higher OTV participants had lower cognitive inhibitory scores, talked more, were less interested in their partners, and focused more on themselves. Their conversational partners were less satisfied. Age and cognitive functioning were not related to OTV scores or conversational style for low- and mid-range participants. Although high-OTV individuals talked less when exposed to social cues signalling boredom, they spoke more relative to other participants. Self-reported social behavior had little relation with OTV and conversational style, but higher OTV individuals were less accurate in judging videotaped social interactions. Gender differences in conversational behavior are also discussed.

Everyday activity parameters and competence in older adults.

Parameters of everyday activities in relation to cognitive, social, and emotional competence were examined in 2 studies. The parameters included frequency, difficulty, importance, intentions for future activities, changes in past activities, and ability of performance. The challenge hypothesis, in which performance of optional activities experienced as moderately difficult is associated with greatest well-being, was also tested. Two samples of older adults completed a life history interview and measures of psychological functioning. Parameters of activities necessary for maintaining an independent engaged lifestyle were measured by the Everyday Activities Questionnaire. In both studies, competence variables helped explain activity parameters independently of age and demographic variables. There was no support for the challenge hypothesis in either study.

Measurement of Activity in the Elderly: The Activities Checklist

This study assessed the reliability and validity of the Activities Checklist (Reid & Ziegler, 1981) as well as its utility for predicting cognitive functioning in the elderly. Data were drawn from two longitudinal projects where elderly subjects had been tested on two occasions approximately five years apart. Test-retest reliabilities were .54 and .43 for the larger ( N = 158) and smaller ( N = 76) samples respectively. Validity was demonstrated by an age shift towards more passive activities and by positive correlations with education, occupational status, health and well-being. Weighted versions of activity scores were not superior to unweighted versions as predictors of cognitive functioning. For both samples activity levels significantly predicted performance on some cognitive measures. It was concluded that the Activities Checklist is a potentially useful instrument to employ in the study of individual differences in cognitive aging.

The effects of concurrent tasks on reading: Implications for phonological recoding

Abstract The use of phonological codes in normal reading was investigated in three experiments in which subjects were asked to read and comprehend prose passages while simultaneously performing concurrent tasks. These tasks differed in terms of stimulus type (verbal-nonverbal), response mode (articulatory-nonarticulatory), and stimulus-response congruence (transformation required-not required). A statistical adjustment procedure was used to take into account the general processing capacity required by the concurrent tasks. After the general capacity demands of these tasks were measured and partialled out, their specific interference with reading was shown to be related to whether or not the input required transformation, and to be unrelated to stimulus type or response mode. Concurrent tasks, such as shadowing, which required an articulatory response but no transformation, only interfered with normal reading when the processing demands of the concurrent task were not taken into account. This suggests that previous findings in which shadowing interfered with normal reading may have been due to a reduction in general processing capacity by the concurrent task, rather than to speech-specific interference. A fourth experiment showed that shadowing did interfere when the reading task was structured so as to force subjects to use phonological codes. Since shadowing did have the potential to interfere with the readers use of phonological codes, but did not interfere with normal reading, the results suggest that skilled reading may not require the use of phonological codes.

Models of intelligence in late life: comment on Hultsch et al. (1999).

The authors comment on D. F. Hultsch, C. Hertzog, B. J. Small, and R. A. Dixons (1999) report of the latest results of the Victoria Longitudinal Study, which are presented as a test of the engagement hypothesis, and on their reanalysis of the data from the Veterans Study (Pushkar Gold et al., 1995), which proposes an alternative model of intellectual function. Differences between the methodologies, variables, and concepts of engaged lifestyle in the 2 studies lead to different tests of the engagement hypothesis and different conclusions. Failure to report specified paths and unjustified assumptions lessen the credibility of the Hultsch et al. model for the Veterans Study data. The authors conclude that their original model, which indicates a small but significant effect of engaged adult lifestyle on the maintenance of intellectual verbal abilities in later life, provides a better explanation of the Veterans Study data.

13 Interactions Between Personality and Cognition and Their Implications for Theories of Aging

Publisher Summary This chapter discusses the interactions between personality and cognition and their implications for theories of aging. Current research on the development of personality and cognition during adulthood increasingly reflects a theoretical emphasis on contextual approaches. These approaches make the assumption that environmental contexts are important determinants of the development both of personality and of cognitive abilities. The processes underlying development are thus viewed as a lifelong series of mutually-causal interactions between the individual and the environment. These theoretical approaches emphasize the variability or plasticity of development, although the continuity of development is also well recognized. Adult characteristics are regarded not as the inevitable outcome of a developmental trajectory determined earlier in life, but are thought of rather as reflecting and shaping the environmental exchanges in which the individual engages in an attempt to maintain a sense of continuity throughout life.

Off-Target Verbosity and Talkativeness in Elderly People.

This study examined whether off-target verbosity should be conceptualized as a distinct process from high levels of talkativeness in every day social situations. The relationship of age to these speech styles was also determined. The responses of 125 community-based elderly adults to a life-history interview were independently rated by two research assistants for the frequency and extent of off-target verbosity. The participants activities in daily life, including talkativeness, were independently rated by the participants themselves, 125 similar-aged peers and 10 professional workers acquainted with the participants. Confirmatory factor analysis supported a model postulating off-target verbosity and talkativeness as two largely independent latent factors. Age was associated with the verbosity factor. The results were interpreted as indicating that off-target verbosity cannot be explained by the same processes that underlie social talkativeness. Possible mechanisms of the verbosity factor were discussed.

Off-Target Verbosity, Everyday Competence, and Subjective Well-Being

Background: Off-target verbosity (OTV), defined as prolific speech that is lacking in focus, is exhibited by relatively few older adults, but increases in prevalence with age. Objective/Methods: The hypothesis that a high level of OTV is associated with declining competence in other aspects of everyday life was examined in 142 older adults, previously screened for the level of OTV. Competence was assessed based on self-reported changes since age 50 years in quality and quantity of engagement in eleven domains of instrumental and voluntary activities of everyday life. Results: Path models indicated that a high level of OTV was associated with a decreased competence in everyday activities and was indirectly linked, through competence, with lower well-being and greater loneliness. With competence level controlled, a high level of OTV directly predicted less loneliness. Conclusions: These findings support the hypothesis that a high level of OTV is symptomatic of a more general decline in competence and of less successful aging. However, a high level of OTV also entails a strong motivation for talking to others and thus may offer protection against loneliness.