Breadth is key to critical thinking and education—empirics

Using a skill theory lens, course-taking breadth can be viewed as contextual support for the development of complex cognitive reasoning skills. This is primarily because: (a) there’s evidence for broad learning experiences improving cognition and (b) students who are exposed to new and different learning experiences are positioned to apply the transformation rules which lead to micro and/or macro skill development. We succinctly elaborate on these two points directly below. Broad learning supports reasoning. Broad learning is posited in work independent from skill theory as contributing to adult cognitive development (Leanos, Coons, Rebok, Ozer, & Wu, 2019; Lovd ¨ ´en, Garzon, ´ & Lindenberger, 2020; Wu, Rebok, & Lin, 2016; Wu, 2019; Chan & Carlson, 2017; Sheffler et al., 2022). In higher education classrooms specifically, a diversity of experiences relates positively to the development of cognitive skills (Loes, Pascarella, & Umbach, 2012). The experience of curricular rigor—which is elicited when conceptual demands are placed on students, requiring the need to reconcile and synthesize disparate information—has also been linked with gains in critical thinking skills after the first and fourth year of college (Culver et al., 2019; 2021). And liberal arts colleges, known for their curricular breadth and organized instruction, have been shown to improve critical thinking skills in large-scale empirical studies (Braun, 2019; Pascarella, Wang, Trolian, & Blaich, 2013; Wang & Xu, 2021). Students are positioned to apply transformation rules. Aside from increasing the likelihood that reasoning skills will be elicited in explicit assignments and tasks (Janssen et al., 2019), curricular breadth increases exposure to different subject matter, peers with dissimilar personalities and worldviews, and instructors with different professional backgrounds and pedagogical practices (Orona, 2021a; Vedel, 2016; Virtanen & Tynjal ¨ a, ¨ 2018; Vu, 2017; Xu & Ran, 2022; Thonney & Montgomery, 2019; Tolppanen, Kang, & Riuttanen, 2022). Thus, it’s hypothesized from skill theory that students with greater course breadth are positioned to apply the transformation rules for developing reasoning capacities since students must utilize existing skill levels and knowledge to navigate novel phenomena and concepts (and people). For example, a student well-versed in reconciling opposing interpretations of historical import (e.g., why the United States withdrew from Vietnam) has a preliminary set of skills to apply when reconciling opposing interpretations of human behavior in psychology. However, since the facts, features, and epistemic criteria differ vastly, it spurs a combination (e.g., compounding) of existing skills and a generalization to a new area (e.g., substitution), leading to increasingly complexity of the skill and thus control over more sources of variation. King and Kitchener (1994, p. 35) summarize how this occurs: “…an individual may not be challenged to try to make sense of discrepancies between the competing views of different authorities because he or she has not previously been asked to compare or contrast such views. When the juxtaposition does occur, as may happen in an educational setting, it stimulates the person to work out a coordination of skills. As the skills are coordinated across levels, they are transformed into new skills. Without challenges that span different types of skills, a person’s existing skill level will probably not change or develop into higher-order skills.”.