Studies investigating evolutionary theories on the origins of national differences in intelligence have been criticized on the basis that both national cognitive ability measures and supposedly evolutionarily informative proxies (such as latitude and climate) are confounded with general developmental status. In this study 14 Y chromosomal…

The failure to correctly report two targets ("T[subscript 1]", "T[subscript 2]") that follow each other in close temporal proximity has been called the "attentional blink" (AB). The AB has, so far, mainly been studied using experimental approaches. The present studies investigated individual differences in AB performance, revealing (among further…

The relation between mental ability and the ability to detect violations of an abstract, third-order conjunction rule was examined using event-related potential measures, specifically mismatch negativity (MMN). The primary objective was to determine whether the extraction of invariant relations based on abstract conjunctions between two…

Many explanations have been proposed for the evolution of our anomalously large brains, including social, ecological, and epiphenomenal hypotheses. Recently, an additional hypothesis has emerged, suggesting that advanced cognition and, by inference, increases in brain size, have been driven over evolutionary time by the need to deal with…

Self-perceived abilities (SPA), which play an important role in academic achievement, have been recently reported to be fully attributable to genetic and non-shared environmental influences. To replicate and extend this finding, 732 Croatian twins (15-22 years old) were assessed on cognitive ability, self-assessed intelligence (SAI), and Five…

The cognitive abilities involved in the Connections (Salthouse, et al., 2000) version of the trail making test were investigated by administering the test, along with a battery of cognitive tests and tests of complex span and updating conceptualizations of working memory, to a sample of over 3600 adults. The results indicate that this variant of…

Spearman's law of diminishing returns (SLODR) posits that at higher levels of general cognitive ability the general factor ("g") performs less well in explaining individual differences in cognitive test performance. Research has generally supported SLODR, but previous research has required the a priori division of respondents into…

Individual differences in general mental ability ("g") have important implications across multiple disciplines. Research suggests that the variance in "g" may be due to a general fitness factor. If this is the case, a relationship should exist between "g" and other reliable indicators of fitness. Some empirical results indicate a relationship…

Individual differences in mental ability (MA) were examined with event-related potentials (ERP). In addition to using an auditory frequency discrimination task, a duration discrimination task was used to elicit P300 and mismatch negativity (MMN) components of the ERP. Frequency and duration P300 latencies explained 9% and 10% of variance of MAB…

The nature of fluid intelligence was investigated by identifying variables that were, and were not, significantly related to this construct. Relevant information was obtained from three sources: re-analyses of data from previous studies, a study in which 791 adults performed storage-plus-processing working memory tasks, and a study in which 236…

There is increasing evidence relating psychometric measures of general intelligence and reasoning to regional brain structure and function assessed with a variety of neuroimaging techniques. Cognitive dimensions independent of general intelligence can also be identified psychometrically and studied for any neuroanatomical correlates. Here we…

General cognitive ability ("g") does not explain sex differences in academic test performance by the end of compulsory education. Instead, individual differences in specific reasoning abilities, after removing the effects of "g," may contribute to the observed gender gaps. Associations between general or specific cognitive…

The purpose of this study was to investigate sources of inter-individual differences in current events knowledge. The study occurred in two sessions. In the initial session, 579 participants completed tests to ability, personality, and interest factors, as well as prior knowledge of current events. Approximately 10 weeks later, participants…

Gardner [Gardner, H. (2006-this issue). On failing to grasp the core of MI theory: A response to Visser et al. "Intelligence"] criticized some aspects of our empirical examination [Visser, B. A., Ashton, M. C., & Vernon, P. A. (2006-this issue). Beyond "g": Putting multiple intelligences theory to the test. "Intelligence"] of his "Theory of…

Taking into account various models and findings pertaining to the nature of analogical reasoning, this study explored quantitative and qualitative individual differences in intelligence using latency and eye-movement data. Fifty-five university students were administered 14 selected items of the Raven's Advanced Progressive Matrices test. Results…