A psychometric investigation of group differences in mean and variability as measured by the Raven's Standard Progressive Matrices Plus

Researchers and the general public alike continue to debate ‘which is the smarter sex?’ Research to date suggests that males outperform females, females outperform males, while others find no differences in mean or variance. These inconsistent results are thought to occur for two reasons. First, studies rely on opportunity samples rather than samples that represent the general population. Second, researchers have not availed themselves of advances in psychometrics that allow for identification of bias in test items and the reliable evaluation of group differences. This dissertation addresses these two identified needs in the literature. Using a large representative U.K. sample, 926 seven to 18 year olds were assessed with the Raven’s Standard Progressive Matrices Plus (SPM+), a measure considered to be one of the best measures of general intelligence. In assessing a one-factor model of general intelligence, four research aims were addressed. First, confirmatory factor analyses and assessment of measurement invariance revealed that the SPM+ is not biased to either sex. Second, multiple group confirmatory factor analyses revealed there to be no significant differences between males and females in either mean or variance. Third, analyses revealed no significant sex differences in mean or variability in younger or older participants. Finally, method effects of Gestalt and Visuospatial answering strategies explained some of the residual variance in the model. For the overall sample, males were significantly disadvantaged by the visuospatial element of some of the items. For older participants, the influence of the methods effects was equivalent. It can generally be concluded that there are no significant sex differences in mean or variability on the SPM+ suggesting that there is no sex difference in general intelligence. Future research should employ representative samples and robust statistical methodologies to assess sex differences on the Raven’s from a multiple factor perspective

Ongoing Themes in Psychology and Culture

Selected Papers from the Sixteenth International Congress of the International Association for Cross-Cultural Psychology, 2002, Yogyakarta, Indonesia. (c) 2004, International Association for Cross-Cultural Psychologyhttps://scholarworks.gvsu.edu/iaccp_proceedings/1007/thumbnail.jp

Cognitive, Neural, and Educational Contributions to Mathematics Performance: A Closer Look at the Roles of Numerical and Spatial Skills

The principal aims of this thesis were to (1) provide new insights into the cognitive and neural associations between spatial and mathematical abilities, and (2) translate and apply findings from the field of numerical cognition to the teaching and learning of early mathematics. Study 1 investigated the structure and interrelations amongst cognitive constructs related to numerical, spatial, and executive function (EF) skills and mathematics achievement in 4- to 11-year old children (N=316). Results revealed evidence of highly related, yet separable, cognitive constructs. Together, numerical, spatial, and EF skills explained 84% of the variance in mathematics achievement (controlling for chronological age). Only numerical and spatial skills, but not EF, were unique predictors of mathematics performance. Spatial visualization was an especially strong predictor of mathematics. Study 2 examined where and under what conditions spatial and numerical skills converge and diverge in the brain. An fMRI meta-analysis was performed to identify brain regions associated with basic symbolic number processing, mental arithmetic, and mental rotation. All three cognitive processes were associated with activity in and around the bilateral intraparietal sulcus (IPS). There was also evidence of overlap between symbolic number and arithmetic in the left IPS and overlap between mental rotation and arithmetic in the middle frontal gyri. Together, these findings provide a process-based account of common and unique relations between spatial and numerical cognition. Study 3 addressed the research-to-practice gap in the areas of numerical cognition research and mathematics education. A 25-hour Professional Development (PD) model for teachers of Kindergarten–3rd Grade was designed, implemented, and tested. Results indicated that the PD was effective at increasing teachers’ self-perceived numerical cognition knowledge and students’ general numeracy skills. However, there were notable differences in the effects of the PD across the two sites studied, with much stronger effects at one site than the other. Thus, critical questions remain as to when and why the model may be effective in some school contexts but not others. Together, these studies contribute to an improved understanding of the underlying relations amongst spatial, numerical, and mathematical skills and a viable new approach to better integrate research and practice