CHC cognitive abilities, executive functions, cognitive styles, and reading achievement in children aged 8 to 12: tests of multiple mediation and moderation

Poor reading achievement continues to be a major social and political issue, with 4.5% of students in year 3 and 6.2% of students in year 5 in Australia achieving below minimum standards in reading, as identified in the recent National Assessment Program -- Literacy and Numeracy (NAPLAN) testing (Ministerial Council on Education Employment Training and Youth Affairs, 2012). Taking advantage of recent advances in psychometrically driven modelling in cognitive science, this dissertation sought to contribute with these to furthering an understanding of the cognitive processes that explain variations in children’s reading achievement. The study involved a quantitative cross-sectional design involving 231 Australian elementary school children, aged 8 to 12. Participants were tested on a broad range of Carol-Horn-Cattell (CHC) defined cognitive abilities, executive functions, cognition-centred and personality-centred cognitive styles, and reading achievement. Structural equation modelling using MPlus was employed to compare multiple mediation models, determining the statistical significance of each separate mediation effect in the model, and comparing effect sizes. Results indicated that a four-level fully mediated cascade model looks like it offers the best representation of the cognitive mechanism that explains variance in reading scores. There was one exception, a significant mediation of processing speed on the relationship between age and crystallised intelligence. This model showed that age (level 1) affects processing speed (level 2), which directly affects visual short-term memory, verbal short-term memory, inhibition, updating and crystallised intelligence (level 3). In turn, visual and verbal short-term memory and crystallised intelligence directly affect reading achievement (level 4). This model explained 94% of the variance in reading scores. A surprising and novel result was a moderate significant negative relationship between visual short-term memory and reading achievement (β = -.46, 95% CI [0.32-.88]). Inhibition and updating did not significantly relate directly to reading. Moderated mediation analysis was used to test the conditions under which the cognitive mechanism explaining variation in reading is true. Results indicated that none of the cognitive styles used in the study were significant moderators. The study included the following cognitive styles: Reflection-Impulsivity, Wholistic-Analytical, Introverted-Extroverted, Intuition-Sensing and Judging-Perceiving, as well as thinking Creatively, Unconventionally, Technically, Open/Positively, Convincingly, and in an Idea-ist way. Further, this dissertation sought to contribute to a psychometric evaluation of two personality-centred cognitive style measures. Exploratory structural equation modelling (ESEM) was used as part of the validation process for the Murphy-Meisgeier Type Indicator for Children (MMTIC) and a newly developed questionnaire, the Children’s Ways of Thinking questionnaire (C-WOT). Results indicated the structure of the 70-item MMTIC is inadequately differentiated, but promising validation results were found for a refined 22-item version. Evaluation of the 133-item draft C-WOT showed that a 29-item, six-factor version of the scale had good internal consistency, factor determinacy and adequate discriminant and construct validity, making it a potentially useful tool for evaluating cognitive style in children. The study findings suggest that visual short-term memory are more important factors in children’s reading achievement than currently acknowledged, and cognitive style is a less important factor, with important implications for their place in psycho-educational assessment as a sound basis for planning interventions and accommodations. Further worthwhile research with children aged 8 to 12 from the normal population is indicated to validate the study findings. A thesis submitted in partial fulfilment of the requirements of the Master of Psychology (Educational and Developmental) / PhD, Department of Education, Monash University