development

Do the smart get smarter? Development of fluid and crystallized intelligence in 3rd grade

IntelligenceReference. Schroeders, U., Schipolowski, S., Zettler, I., Golle, J., & Wilhelm, O. (2016). Do the smart get smarter? Development of fluid and crystallized intelligence in 3rd grade. Intelligence, 59, 84–95. https://doi.org/10.1016/j.intell.2016.08.003

Abstract. There are conflicting theoretical assumptions about the development of general cognitive abilities in childhood: On the one hand, a higher initial level of abilities has been suggested to facilitate ability improvement, for example, prior knowledge fosters the acquisition of new knowledge (Matthew effect). On the other hand, it has been argued that school education with its special focus on promoting less able students results in a compensation effect. A third hypothesis is that the development of cognitive abilities is—as an outcome of the opposing effects—overall independent of the initial state. In this study, 1,102 elementary students in 3rd Grade worked on two versions of the Berlin Test of Fluid and Crystallized Intelligence at two time points with an interval of five months. Beside the question of how initial state and growth are related (Matthew vs. compensation effect), we considered performance gains in fluid intelligence (gf) and crystallized intelligence (gc) as well as cross-lagged effects in a bivariate latent change score model. Both for gf and gc there was a strong compensation effect. Mean change was more pronounced in gf than in gc. We considered student characteristics (interest and self-concept), family background (socio-economic status, parental education) and classroom characteristics (teaching styles) in a series of prediction models to explain these changes in gf and gc. Although several predictors were included, only few had a significant contribution. Several methodological and content-related reasons are discussed to account for the unexpectedly negligible effects found for most of the covariates.

Age-related changes in the mean and covariance structure of fluid and crystallized intelligence in childhood and adolescence

IntelligenceReference. Schroeders, U., Schipolowski, S., & Wilhelm, O. (2015). Age-related changes in the mean and covariance structure of fluid and crystallized intelligence in childhood and adolescence. Intelligence, 48, 15–29. doi:10.1016/j.intell.2014.10.006

Abstract. Evidence on age-related differentiation in the structure of cognitive abilities in childhood and adolescence is still inconclusive. Previous studies often focused on the interrelations or the g-saturation of broad ability constructs, neglecting abilities on lower strata. In contrast, we investigated differentiation in the internal structure of fluid intelligence/gf (with verbal, numeric, and figural reasoning) and crystallized intelligence/gc (with knowledge in the natural sciences, humanities, and social studies). To better understand the development of reasoning and knowledge during secondary education, we analyzed data from 11,756 students attending Grades 5 to 12. Changes in both the mean structure and the covariance structure were estimated with locally-weighted structural equation models that allow handling age as a continuous context variable. To substantiate a potential influence of school tracking (i.e., different learning environments), analyses were additionally conducted separated by school track (academic vs. nonacademic). Mean changes in gf and gc were approximately linear in the total sample, with a steeper slope for the latter. There was little indication of age-related differentiation for the different reasoning facets and knowledge domains. The results suggest that the relatively homogeneous scholastic learning environment in secondary education prevents the development of more pronounced ability or knowledge profiles.