Structural extensions of a hierarchical view on human cognitive abilities

Individual differences research has always been open to interaction with other areas of psychology and with neighboring disciplines in both the sciences and humanities. Virtually all psychometric tests of abilities originate from experimental cognitive psychology. Nevertheless, throughout the history of our discipline, there have been periodic attempts to explain its main findings in terms of some basic biological or sociological influence. Perhaps unfortunately, such attempts have produced unconvincing outcomes. The latest significant move has been from a reductionistic, physical perspective. These studies, in general, are poorly designed (Mackintosh, 1998) and/or may be driven by dubious motivations (Ceci, 1996). An entirely different attitude has emerged from within the educational sphere, where contexrual and metacognitive perspectives are at least as dominant as reductionistic approaches. By and large, studies carried out from within this latter perspective have left a considerably weaker impact than biological approaches on mainstream research into human cognitive abilities. I suspect that the reason for the lack of a systematic attempt at linking metacognitive processes to intelligence derives from a concern that the measurement of these processes is imprecise and "unscientific," certainly in comparison to the properties of physical measurement. This is not entirely justified (see Stankov, 2001; Stankov & Roberts, 1999). Our own work has followed a general strategy of seeldng an improved understanding of sources of individual differences - both biological and sociological/educational - for some well-established cognitive traits. The whole gamut of potential sources, including those uncovered by the experimental research within the mainstream psychology, has been considered. My purpose here is to briefly review some of our recent work, published or awaiting publication, on the cognitive bases of fluid intelligence (Gf) and mental speed. Additionally, I propose to review our work in hitherto poorly researched areas of human abilities and on borderline areas between ability and personality traits.