A general model for the study of developmental problems.

Various research designs employed in developmental psychology for the investigation of maturational and aging effects are examined. Discrepancies and contradictions in the conclusions derived from cross-sectional and longitudinal studies are consequences of the violation of assumptions implicit in these research designs. The conventional methods are shown to be special cases of a general model for research on behavior change over time. The properties of the general model are explicated and the assumptions for the customary designs are reviewed in the light of these properties. The complete model requires consideration of the components of age, time and cohort differences in the identification of developmental change. Both the longitudinal and cross-sectional methods in this context require strong assumptions which can rarely be met. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Fourteen-year cohort-sequential analyses of adult intellectual development.

Provides a comprehensive analysis of data from 412 Ss (mean ages 22–67 yrs at 1st test) on the Primary Mental Abilities Test. Ss took part in 1 of 2 longitudinal sequences, 1956–1970 or 1963–1977. Comparable data are also reported on cross-sectional sequences collected in 1956, 1963, 1970, and 1977. A decline in intelligence became clearly evident after age 60 yrs, with from a third to a half standard deviation decrement over a 14-yr period. Contrary to earlier reports (e.g., K. W. Schaie and I. A. Parham, 1977), small but significant decrements were noted over the 53–67 yr age range. Cohort/sequential cohort effects, which were not attributable to age changes, were found for several subtests. (28 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Ageism in psychological research.

Insufficiently informed psychologists may draw erroneous or incomplete conclusions from their research findings that result in public representations that enhance adverse stereotypes held with respect to the elderly. Such inappropriate interpretations of age-related data may become accepted as the scientific basis for policy positions that lead to discrimination against and disadvantages for our older citizens. This article identifies major sources of ageist bias in psychological research that may inadvertently result in adverse consequences for the elderly. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

"Perceptual speed in adulthood: Cross-sectional and longitudinal studies": Correction.

Reports an error in the original article by K. Warner Schaie (Psychology & Aging, 1989[Dec], Vol 4[4], 443–453). On page 449, some of the data in Table 8 were computed with an incorrect algorithm. The corrected table, which does not change the conclusions of the article, is included. (The following abstract of this article originally appeared in record 1990-09502-001.) Cross-sectional data on age differences in perceptual speed are presented from the Seattle Longitudinal Study for the age range 22–91 years (N?=?1,620, first assessed in 1977; N?=?628, first assessed in 1984). In addition, 838 subjects were followed over the 7-year interval. Markers of perceptual speed were the Identical Pictures and Finding A's tests from the Educational Testing Service's Kit of Factor-Referenced Cognitive Tests. Significant age differences, age changes, and cohort differences were found at both observed variable and latent construct levels. Cross-lagged correlations examine the role of perceptual speed in predicting later performance on other abilities (Verbal Meaning, Inductive Reasoning, Spatial Orientation, Number, and Word Fluency).… (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

On the plasticity of intelligence in adulthood and old age: Where Horn and Donaldson fail.

Challenges the critique by J. L. Horn and G. Donaldson (see PA, Vol 57:Issue 4) of the K. W. Schaie and P. B. Baltes research and writings on intelligence in adulthood and old age, contending that it seriously misrepresents Schaie's and Baltes's theoretical positions and data interpretations. It is noted that Schaie and Baltes do not reject in toto the notion of intellectual decline; within the framework of a dialectical interpretation of intelligence in adulthood and old age, they emphasize plasticity as evidenced in large interindividual differences, multidimensionality, multidirectionality, modifiability, and the joint import of age- and cohort-related determinants. When arguing for the adequacy of a fluid-crystallized model of intelligence, Horn and Donaldson's critique conveniently de-emphasizes the empirical significance of cohort effects. Contrary to a process-oriented dialectical view, the critique (assuming fairly invariant and fixed change patterns) espouses a model of adult gerontological development which Schaie and Baltes judge to be anachronistic. It is concluded that Horn and Donaldson present a reactionary critique which, if taken too seriously, is likely to inhibit much-needed progress in the field of intelligence in adulthood and old age. (30 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cohort-sequential analyses of adult intellectual development.

Conducted cohort-sequential analyses over a 7-yr interval on measures from the Primary Mental Abilities Test and the Test of Behavioral Rigidity on a sample of 2,151 participants at 1st test (independent random samples study, IS) and 723 individuals who returned for retest after 7 yrs (repeated measurement study, RM). Data were examined for 7-yr age intervals from 25 to 81 yrs, and cohort intervals from 1889 to 1938. Data sets were replicated for periods beginning in 1956 and 1963, respectively. Previous contentions of substantial plasticity in adult intellectual development were supported. Reliably demonstrable within-cohort-decrement occurred only late in life and not for all variables examined. Proportions of variance for ontogenetic change were generally smaller than for cohort differences. Estimated proportionate cumulative decrement at age 67 placed mean values below the range of average 25-yr-olds only for Word Fluency (RM and IS) and for Inductive Reasoning and Space (IS study). By contrast, similar estimates for cohort differences cumulated over a time period equivalent to the age range from 25 to 67 place the mean level of the oldest cohort below the average range of the youngest cohort for most variables examined. (24 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Perceptual speed in adulthood: Cross-sectional and longitudinal studies.

Cross-sectional data on age differences in perceptual speed are presented from the Seattle Longitudinal Study for the age range 22–91 years (N?=?1,620, first assessed in 1977; N?=?628, first assessed in 1984). In addition, 838 subjects were followed over the 7-year interval. Markers of perceptual speed were the Identical Pictures and Finding A's tests from the Educational Testing Service's Kit of Factor-Referenced Cognitive Tests. Significant age differences, age changes, and cohort differences were found at both observed variable and latent construct levels. Cross-lagged correlations examine the role of perceptual speed in predicting later performance on other abilities (Verbal Meaning, Inductive Reasoning, Spatial Orientation, Number, and Word Fluency). When perceptual speed is partialled out of scores for these abilities, aging effects are reduced markedly for all abilities, but least for Spatial Orientation and Inductive Reasoning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of cognitive training on primary mental ability structure.

We report results of the first empirical test, as far as we know, of the assumption of structural invariance of latent constructs from pretest to posttest in cognitive training research on the elderly. In all, 401 participants in the Seattle Longitudinal Study, over 62 years old, received a 5-hr test battery at pre- and posttest that included 16 ability tests, marking the five primary abilities of Spatial Orientation, Inductive Reasoning, Numerical Ability, Verbal Ability, and Perceptual Speed. A total of 229 of our subjects received 5 hrs of individual training on either Spatial Orientation or Inductive Reasoning. Restricted factor analysis with the {lisrel} algorithm tested the hypothesis of measurement equivalence across test occasions, separately for the control subjects and for each of the training groups. When ability-specific cognitive training intervenes, no structural change is observed for abilities not subject to intervention. However, slight shifts occurred in the optimal regression weights for the different markers for the training target abilities. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The relationship between advanced age and mental abilities.

Scores on primary mental abilities, speed, memory, and motor rigidity were obtained from 50 college graduates ranging in age from 70 to 84 years. A cross sectional study demonstrates a differential decline in these abilities with advancing age. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Can decline in adult intellectual functioning be reversed?

Examined whether or not cognitive decline in the elderly that has been reliably demonstrated over a 14-yr period can be reversed. 97 male and 132 female participants (aged 64–95 yrs) in a long-term longitudinal study were classified into those who had declined (n?=?122) and those who had remained stable (n?=?107) on the abilities of inductive reasoning and spatial orientation, based on their performances on the Primary Mental Ability Reasoning and Spatial Orientation Tests. Ss were assigned to 5-hr training programs on either ability in a pretest–posttest design that used Ss trained on 1 target ability as controls for those trained on the other. Results show that cognitive training techniques reliably reverse decline in spatial and reasoning ability documented over a 14-yr period in a substantial number of Ss. Training procedures also enhanced the performance of many Ss who had remained stable. Training improvement on spatial orientation was found to be greater for decliners than for those who remained stable and greater for females than for males. (36 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)