Gold Open Access: This paper is published under the terms of the CC-BY-NC license.

Spatial reasoning is critical for success in science, technology, engineering, and mathematics (STEM) disciplines and particularly for geoscience. To evaluate capabilities among U.S. students, we assessed spatial reasoning skills in 345 introductory geology and upper-level structural geology students. The test measured students’ abilities to disembed, visualize, and mentally rotate objects. The results highlight an uneven distribution of spatial skills with a minimum score of 6% and a maximum score of 75% correct responses. Spatial skills are positively correlated with standardized test scores, motivation for learning, STEM major declaration, and number of science courses taken. Our analysis also indicates that the cumulative, informal training of childhood play has the ability to increase spatial reasoning. Spatial skill scores were significantly higher among students who played action, construction, or sports video games in childhood. Male and female students display significant differences in spatial skills, especially for mental rotation, with males outperforming females. However, gender disparities are fully mediated after adjusting for a variety of academic factors and whether students frequently played with construction-based toys. This indicates that gender differences are experiential rather than biological in origin. This study suggests that both formal academic training and extracurricular activities appear to develop spatial skills throughout students’ lives and indicates that systematic testing of spatial skills and formal training opportunities for students would facilitate improved spatial reasoning among students. We hypothesize that formal training opportunities for spatial reasoning could increase the potential pool of students who successfully enter STEM careers, including the geosciences, especially among women.