Many aspects of cognition decline from middle to late adulthood, but the dimensionality and generality of this decline have rarely been examined. We analyzed 20-year longitudinal data of 6203 middle-aged to very old adults from Greater Manchester and Newcastle-upon-Tyne, UK. Participants were assessed up to eight times on 20 tasks of fluid…

Tested whether tonic EEG power is related to memory performance by analyzing ongoing EEG for 60 subjects in 5 experimental conditions. Subjects with good memory performance had significantly larger upper alpha power, but less theta and lower alpha power. Also discusses findings for subjects good at calculation. (SLD)

The relationship between reasoning ability, as indicated by performance on conventional reasoning tests, and working memory capacity was investigated in 4 studies involving 723, 412, 414, and 595 military recruits, respectively. The results demonstrate a consistently high correlation between general reasoning ability and general working-memory…

Memory-based searching was compared in 15 developmentally delayed and 24 normal two-year-olds. In a relatively easy memory task, individual differences were minimal, but searching for a plausible alternative location based on memory revealed marked individual differences and an important difference in the cognitive functioning of the delayed…

Individual differences in procedural and declarative learning of a sequence-learning task by 455 adolescents were measured and compared to one another and to scores on a performance battery. A framework is proposed to explain the results based on a combination of approaches to explain dissociations found in memory. (SLD)

A case is made for the construction of nomothetic theories that can also explain individual differences. The discussion uses examples from the memory area and presents an approach to memory that explains individual findings and individual differences in the context of a single model. (SLD)

Individual differences in retention, with an emphasis on their relationship with learning speed and other cognitive factors, were studied in 685 military recruits. In all of the forgetting conditions, the fastest learners remembered more and relearned faster. Results support the existence of individual differences in retention. (SLD)

In experimental time estimation research, it has consistently been found that the more a person is engaged in some kind of demanding cognitive activity within a given period of time, the more experienced duration of this time interval decreases. However, the role of individual differences has been largely ignored in this field of research. In a…

Research on educable retarded children is reviewed to explicate components of and a theory of intelligence. Studies of control processes in memory and problem solving indicate that the ability to generalize is a major component of intelligence. Research on individual differences in components of information processing systems are also discussed.…

To clarify the relationships between reaction time (RT) variability and intelligence, RT distributions from 303 male Navy recruits were partitioned into 16 fast-to-slow latency bands calculated with measures of mental ability. The slowest bands (worst trials) were the best predictors of intelligence and working memory performance. (SLD)

Sternberg and Gastel have provided an example of a major principle of intelligence research--the relationship between a task's working memory demands and its sensitivity to individual differences in fluid intelligence and "g." There is no need to invoke additional constructs such as "novelty." (SLD)

Two studies involving 333 military recruits investigate individual differences in time-accuracy functions of inspection time (IT) in terms of psychological models. Two alternative interpretations of IT time-accuracy functions (processing-distraction and processing-speed, and pure processing-speed "cascade" models) are considered in…

The latency and amplitude of the P300, an event-related potential, during the performance of a memory-scanning task were used as indices of the efficiency of information processing that may mediate individual differences in intelligence. Results with 61 female college students contradict a pure speed of processing explanation of the relationship…

The relationship between elementary operations underlying processing of numerical information and performance on psychometrically derived ability measures requiring processing of numbers but defining separate ability factors was studied for 102 Air Force recruits (54 males and 48 females). Patterns of convergent and discriminate relationships for…

Measurement and psychometric quality of the Sternberg task (S. Sternberg, 1966, 1969), a memory search task, was investigated with 78 undergraduates. Individual performance was fairly homogeneous across responses, fairly unstable over time, and fairly stable across stimulus content. Implications for individual differences research are discussed.…