Review of hierarchical theories of intelligence

Review of hierarchical theories of intelligence The theories of cognitive abilities have been advanced through the conglomeration of two similar theories on the structure of human cognitive abilities which have provided a trend in intelligence theories. In particular, Cattell (1941) and Horn (1965) theoretical frameworks on unitary traits that reflects certain basic aspect of cognitive functioning (Fogerty Stankov, 1988) along with the seminal work of Carrolls (1993) three stratum theory that proposed cognitive abilities was an expansion and extension of previous theories, notably Spearman (1927) concept of general intelligence (g) have influenced the advancement in understanding the concept of general abilities. McGrew (2004) article emphasizes the theory based assessment, specifically CHC theory based assessment in human cognitive abilities. The article focuses on the history of cognitive abilities theory particularly test development, operationalisation and interpretation and outlines salient points of the model along with evidence review in support of the model. Thus, McGrew (2004) provided an outline describing the conglomeration of these models in particular, the initial works of Cattell (1941) and Horn (1965) Gf Gc theory which proposed Gf (fluid intelligence) of individual differences in cognitive ability were the influences of two major classes of factors, educational-cultural opportunity, genetic factors and physiological neurological functioning (Ferrer McArdle, 2004) that affected the normal development of cognitive abilities and further postulating that Gc (crystallised intelligence) primarily consisted of representation of measurable outcome of additional environmentally infl uenced factors such as experience and acculturation (Alfonso, Flanagan Radwan, 2005. Cited in: Flanagan Harrison (Eds)). According to McGrew (2004), the theory was further expanded by Horn to include various aspects of human cognitive abilities that comprised of eight broad abilities: Fluid Intelligence (Gf), Crystallized Intelligence (Gc), Short-Term Acquisition and Retrieval (SAR or Gsm), Visual Intelligence (Gv), Auditory Intelligence (Ga), Long-Term Storage and Retrieval (TSR or Glr), Cognitive Processing Speed (Gs), Correct Decision Speed (CDS), and Quantitative Knowledge (Gq). (Horn, 1991. Cited in McGrew, Werder Woodcock (Eds)) proposing that the correlation between Gf -Gc is the result of an individuals investment in Gf through the acquisitioning of the variety of information and cognitive skills that represents Gc (Jensen, 2002. Cited in Sternberg Grigorenko (Eds)) as well as suggesting that over the period of interaction with the total environment, individuals who are more highly endowed with Gf attain a higher level of Gc (Fogerty Stankov, 1988) . Evidence in further support of the model relates to Carrolls (1993) seminal work Human Cognitive Abilities: A Survey of Factor-Analytic Studies, which implied that a distinct number of individual differences in cognitive abilities exist and the relationship amongst these factors can be obtained through classification into three different strata (Alfonso, Flanagan Radwan, 2005. Cited in Flanagan Harrison (Eds)). As such, Carroll (1993) represented the structure of intelligence as a pyramid where general intelligence (g) formed the apex as conceptualised by Spearman (Berk, 2000). He believed that g was the most important factor when determining intelligence and that general intelligence could be divided into many more sub-factors, thus he organised these sub-factors into domains of intellectual abilities representing three separate levels and listing these abilities in descending order of predominance (Carroll, 1993). Stratum III general intelligence factor, Stratum II included the a bilities of Fluid Intelligence (Gf), Crystallized Intelligence (Gc), General Memory and Learning (Gy), Broad Visual Perception(Gv), Broad Auditory Perception (Ga), Broad Retrieval Ability (Glr), Broad Cognitive CHC Theory of cognitive abilities Speediness (Gs), and Reaction Time/Decision Speed (Gt), including 69 narrow abilities within Stratum I that are subsumed by stratum II abilities (McGrew, 2004). Similarly, there is evidence to indicate that CHC has since been recognised as being the most thorough and well researched multiple view of intelligence to date ( McGrew, 2005; Evans, McGrew, Leforgee. 2001). More specifically, McGrew (2004) argues that contemporary psychometric approaches have resulted in an effort to present a comprehensive conceptualisation of human cognitive abilities based on factor analytic studies. However, McGrew (2004) concede that although psychometrics had been highly recognised within the field of applied intelligence research it had been a much slower acceptance within the field of intelligence testing. Noting, diversity in test measures as the disparity in the advancement of the CHC theory particularly in defining and interpreting cognitive abilities construct, as well as the non inclusion of fluid and crystallised intelligence along with the exclusion of corresponding research base as a means to the development of intelligent testing (Alfonso, Flanaga n Radwan, 2005). The author argued that the impetus of change within this sphere was due to the revise model of the Woodcock-Johnson Psycho-Educational Battery (WJ-R) based on Horn-Cattell Gf Gc theory as a cognitive model for test development which included two measure of each eight abilities. Moreover, that the amelioration of the WJ-R resulted in the foundation for the first major theory-to-practice bridging with major impact being on the applied measurement of intelligence. This approach of Woodcock (1990) became a blueprint for future intelligence test development thus, substantially influencing narrowing the contemporary psychometric theory and applied practice gap (Alfonso, Flanagan Radwan, 2005). CHC Theory of cognitive abilities McGrew (2004) postulated that as a result of Woodcock (1990) confirmatory factor analyses findings of major intelligences test sparked by the amelioration of the WJ-R permitted the freeing up of practitioners from constraints of most single intelligence batteries. The realisation by practitioners of the provision of a set of principles and procedures consequently from a cross battery approach as suggested by Woodcock (1990), allowed for greater measurement of a wider range of abilities by way of, systematically traversing amongst test batteries that were considered sufficient both in breath and depth in assessing various aspect of the broad range of cognitive abilities (Alfonso, Flanagan Radwan, 2005). The assumption of McGrew (2004) of Woodcocks (1990) work provided a transition in intelligence testing has had ample evidence in the literature (see McGrew Flanagan, 1998; Messick, 1992; Sternberg Kaufman, 1998) to support such a postulation. In the cross batteries approach McGrew Flanagan (1998) proposed the present of the provision of empirically based set of terms that is a standard nomenclature may significantly reduce or eliminate data misinterpretation generally through the combination of cognitive test. Accordingly, Messick (1998) implied that the utilisation of cross batteries approach would safe guards against two ubiquitous sources of invalidity in assessment- construct irrelevant variance and construct under representation. Furthermore, the attributes of cross batteries approach has typically focused on organise assessment that generate and test hypotheses that pertains to an individuals functioning by which reliable and valid conclusions are draw in a systematic mann er (Alfonso, Flanagan Radwan, 2005). It was therefore logical that focus on the structure of human cognitive abilities was of a critical importance given that there were diverse interpretations and understandings of the CHC Theory of cognitive abilities   With the changes in intelligence test development a systematic taxonomic structure was required in the field of intelligence, McGrew (2004) claims Carrolls (1993) seminal work Human Cognitive Abilities: A Survey of Factor-Analytic Studies provided the development of a common nomenclature that is a common set of terms and definition for describing broad and narrow cognitive abilities above and beyond the effect of g (McGrew, 2009). In doing so, Carroll (1993) was able to further the understanding of communication and intelligence measurement amongst scholars and practitioners, integrate and compare individual test across an array of intelligence batteries (McGrew, 2004). Moreover, Carrolls (1993) taxonomy on the structure of human cognitive abilities is grounded by exploratory factor analysis of 461 selected human cognitive abilities datasets, drawn from decades of research by various array of dedicated researchers in the field of intelligence (McGrew, 2004). The influence of the CHC taxonomic framework in the use of applied individual batteries of intelligence had ignited the search for common ground between cognitive and psychometric developments; hence, in McGrew (2004) article he had introduced the term spreading of the assessment gospel suggesting in order to study individual differences in cognitive abilities there needed to be a single broad and narrow ability taxonomy by which the constructs of abilities could be measured in the individually administered intelligence batteries. For this reason, McGrew (2004) is further suggesting that broad abilities should be considered as clusters in the construct of intelligent behaviour and therefore should be considered separately, thus, a move from the concept of single unitary constructs. CHC Theory of cognitive abilities The CHC model in the past decade has seen a series of exploratory and/or confirmatory factor analysis studies investigating the validity of a wide range of CHC constructs indicators. McGrew (2004) claims since Woodcocks (1990) series of joint factor analyses the majority of intelligence test prior to this only measured two or three broad cognitive abilities sufficiently, conceding that Carrolls (1993) was amongst the array of studies. However, it seems clear that although such representations are evident, the CHC theory has had major impact on intelligence test development due to exploratory and/or confirmatory factor analysis investigations that substantially increases research base to provide empirical support for the broad strokes of contemporary CHC theory (McGrew, 2004). McGrews (2004) article elucidate studies findings that support the CHC frame work through a comprehensive depiction of the general and broad abilities and their interrelationship in determining human cognitive abilities, for example multiple group confirmatory factor analysis methodological framework (see Bickley, Keith and Wolf, 1995) found support for the developmental invariance , whilst Taub McGrew ( in press) findings were consistent with that of Bickley et.al (1995) in providing additional support for validity of the broad and general stratum abilities of CHC theory, moreover, small sample structural studies provided a strong support for distinct CHC cognitive factors, however, a depiction is also clear that no single intelligence battery effectively measures all the broad abilities delineated in the framework of CHC (see Kaufman Kaufman, 1993; Pallier and Stankov, 1996). Research using cross batteries intelligence test such as WJ-R and Woodcock -Johnson Psycho-Educational Battery Third Edition (WJ-III) has demonstrated the importance of broad cognitive abilities in explaining domain specific knowledge for generalisation and correlations CHC Theory of cognitive abilities between construct indicators (McGrew, 2004). In his article, McGrew (2004) provides evidence based on major studies and it is easy to conclude from these findings the existence of these broad abilities. For instance, related cognitive abilities in which learning mediates the influence of fluid intelligence (Gf) and crystallised intelligence (Gc) with cognitive constructs such as general sequential, reasoning (RG), language development (LD), listening ability (LS) with other broad abilities; processing speed (Gs) and basic skills (Grw) (reading and spelling, reading comprehension). A central point in much research interest in intelligence theories has been whether general intelligence is embedded in every cognitive task. The CHC theory represents one of the best examples of collective science in applied psychology (McGrew, 2009), with its core origin being able to be pinpointed back to Spearmans (1927) presentation of the g factor of intelligence. The seminal work of Carrolls (1993) three stratum theory has been a major influence in the framework of CHC theory based on factor analysis of 461 datasets. As previously mentioned in this paper, Carroll (1993) believed that g was the most important factor when determining intelligence, evidence of g is able to be obtained when 60 narrow factor abilities (visualization, visual memory, deductive reasoning) of the first stratum are correlated producing a set of eight second stratum factors (fluid intelligence, crystallized intelligence, general memory and learning, broad visual perception, broad auditory perception, bro ad retrieval ability, broad cognitive speediness, and processing speed) which are positively inter-correlated. When these second stratum factors are analysed, a single third factor stratum of general intelligence emerges, whereas, in the two stratum model of Cattle-Horn the second broad order factors constitute the apex and are based on over 40 first-order factors (primary mental abilities) that forms the lower stratum denoting that there is only two general factors (fluid intelligence, CHC Theory of cognitive abilities crystallized intelligence) hence, it does not support a third order g factor to account for correlations among the broad sector order factors (Jensen, 2002). Guided by structural and empirical evidence the CHC theory arbitrate well in relation to general intelligence that is, g is measured depending upon the statistical analysis of measures of human cognitive abilities in determining cognitive strength and weaknesses of an individual. This is evident in McGrew (2004) assertion that working memory (MW) is a source of complex cognitive activities and is a critical issue in future studies (see McGrew Woodcock, 2001) for postulation of constancy of relations of MW to exert a large causal effect on complex performance, particularly in understanding the rise and decline over the life span. Furthermore, McGrew (2004) argues that measurement of specific abilities within the CHC framework is mainly due to disparity of the CHC theory in describing a relatively complete taxonomy of cognitive function, however, excludes other processes, such as directly testing sensory modalities. In doing so, CHC theory neglect other abilities that have found to be important in the construct of intelligent behaviour and achievement. Support for contemporary CHC theory is grounded in the extent of factor analytic research that produced the Gf Gc model and the three stratum model with the necessity of further research (heritability, neurocognitive, outcome criterion) to continue the validation, refinement and extension of the CHC taxonomy being evident in McGrew (2004) article suggesting human cognitive abilities is clearly multidimensional. As such, McGrew (2004) makes clear that Carrolls (1994, cited in McGrew) approach of open-ended empirical theory is a pathway to which future research are able to provide yet unknown and unmeasured factor abilities upon one or more levels of the CHC model. CHC Theory of cognitive abilities