[Article Review] Unlocking the Secrets of IQ Malleability: The Role of Epigenetics and Dopamine D2 Receptor

Reference

Kaminski, J. A., Schlagenhauf, F., Rapp, M., Awasthi, S., Ruggeri, B., Deserno, L., Banaschewski, T., Bokde, A. L. W., Bromberg, U., Büchel, C., Quinlan, E. B., Desrivières, S., Flor, H., Frouin, V., Garavan, H., Gowland, P., Ittermann, B., Martinot, J.-L., Martinot, M.-L. P., Nees, F., Papadopoulos Orfanos, D., Paus, T., Poustka, L., Smolka, M. N., Fröhner, J. H., Walter, H., Whelan, R., Ripke, S., Schumann, G., Heinz, A., & the IMAGEN consortium. (2018). Epigenetic variance in dopamine D2 receptor: a marker of IQ malleability? Translational Psychiatry, 8(169). https://doi.org/10.1038/s41398-018-0222-7

Review

In this article, the authors investigate the association between general IQ (gIQ) and various factors, including polygenic scores for intelligence, epigenetic modification of DRD2 gene, gray matter density in the striatum, and functional striatal activation elicited by temporarily surprising reward-predicting cues. The study includes a sample of 1475 healthy adolescents from the IMaging and GENetics (IMAGEN) project.

The researchers emphasize the significance of understanding the malleability of gIQ and its neurobiological correlates. Their findings indicate the equal importance of genetic variance, epigenetic modification of the DRD2 receptor gene, and functional striatal activation, which influences dopamine neurotransmission. These factors contribute to the variance in cognitive test performance and could potentially explain the "missing heritability" between estimates from twin studies and variance explained by genetic markers.

This study offers valuable insight into the factors that influence gIQ and highlights the need for further research on peripheral epigenetic markers. Specifically, future studies should investigate individual and environmental factors that modify the epigenetic structure, as well as confirm these peripheral markers within the central nervous system in longitudinal settings.

Dissecting Cognition: Spatial vs. Abstract Reasoning at Cogn-IQ.org

In a quest to demystify the structure of cognitive abilities, this study delves into the intricate relationships among various cognitive assessments. Utilizing factor analysis on tasks from the Jouve Cerebrals Test of Induction (JCTI) and the General Ability Measure for Adults (GAMA), two distinct cognitive factors emerged from the data of 118 participants. The first factor, spatial-temporal reasoning, is predominantly associated with tasks involving sequences and construction. The second, abstract reasoning, correlates more closely with matching, analogies, and nonverbal reasoning tasks. These factors could serve as the bedrock for understanding diverse cognitive processes and the interplay between different types of reasoning abilities. 

Despite its findings, the study acknowledges its constraints, including the limited sample size and potential selection bias, pointing towards the necessity for further research with more varied and extensive samples. These findings hold substantial implications for educational strategies, clinical assessments, and professional development initiatives. They underscore the necessity to comprehend the nuanced underpinnings of cognitive tasks to foster interventions and programs that cater to individual cognitive profiles. 

This exploration contributes significantly to our understanding of cognitive testing, offering a scaffold upon which future research might build to enhance the precision of cognitive measurements and their application across various domains.

Link to Full Article: Jouve, X. (2018). Exploring Underlying Factors In Cognitive Tests: Spatial-Temporal Reasoning And Abstract Reasoning Abilities. https://www.cogn-iq.org/articles/exploring-underlying-factors-in-cognitive-tests-spatial-temporal-reasoning-and-abstract-reasoning-abilities.html

[Article Review] Unlocking Potential: How Education Can Improve Intelligence

Reference

Ritchie, S. J., & Tucker-Drob, E. M. (2018). How Much Does Education Improve Intelligence? A Meta-Analysis. Psychological Science, 29(8), 1358-1369. https://doi.org/10.1177/0956797618774253

Review

In this article, Ritchie and Tucker-Drob (2018) explore the relationship between education and intelligence, specifically whether more education leads to increased intelligence. The authors conducted a meta-analysis of 142 effect sizes from 42 data sets, involving over 600,000 participants, using quasi-experimental methods including controlled associations, instrumental variables, and regression-discontinuity designs. The results reveal a consistent, positive effect of education on cognitive abilities, with an increase of 1 to 5 IQ points for each additional year of education.

The authors' robust analysis further highlights the durability of the observed effects, as they persist across various life stages and all broad categories of cognitive ability. This finding is significant, as it suggests that education is a consistent and reliable method for increasing intelligence. By using various research designs, Ritchie and Tucker-Drob (2018) strengthen the validity of their findings, making a compelling case for the importance of continued education in promoting cognitive development.

Overall, the study by Ritchie and Tucker-Drob (2018) offers valuable insight into the impact of education on intelligence, and its findings have important implications for policymakers and educators. The results underscore the significance of investing in education to promote cognitive growth, which can contribute to individual and societal success. This study lays a strong foundation for future research exploring the specific mechanisms through which education may enhance intelligence and cognitive abilities.

[Article Review] Unlocking Potential: The Impact of Growth Mind-Set Interventions on Academic Achievement

Reference

Sisk, V. F., Burgoyne, A. P., Sun, J., Butler, J. L., & Macnamara, B. N. (2018). To What Extent and Under Which Circumstances Are Growth Mind-Sets Important to Academic Achievement? Two Meta-Analyses. Psychological Science, 29(4), 549-571. https://doi.org/10.1177/0956797617739704

Review

In this article, the authors investigated the relationship between growth mindsets and academic achievement. The researchers conducted two meta-analyses to determine the strength of the relationship and the effectiveness of interventions designed to increase growth mindsets on academic achievement.

The first meta-analysis examined the correlation between mindsets and academic achievement, considering potential moderating factors. The second meta-analysis explored the effectiveness of growth mindset interventions on academic achievement, also taking potential moderating factors into account. The overall effects were found to be weak for both meta-analyses. However, the study did provide some support for the theory that students with low socioeconomic status or who are academically at risk could benefit from growth mindset interventions.

This research contributes to our understanding of the importance of growth mindsets in academic achievement. While the overall effects were weak, the findings suggest that targeted interventions for specific groups, such as students with low socioeconomic status or those academically at risk, may yield positive results. Future research should continue to explore the potential benefits of growth mindset interventions and identify additional factors that may influence their effectiveness.