Contents lists available at ScienceDirect Learning and Individual Differences journal homepage: www.elsevier.com/locate/lindif Boys and girls gain in spatial, but not in mathematical ability after mental rotation training in primary education Antonio Rodán a,b , Patricia Gimeno a,c , M. Rosa Elosúa a , Pedro R. Montoro a , María José Contreras a, ⁎ a Universidad Nacional de Educación a Distancia (UNED), Spain b Universidad CEU-San Pablo, Spain c Spanish Ministry of Education, Spain ARTICLE INFO Keywords: Mental rotation Spatial training Sex differences Mathematics Intelligence ABSTRACT Several studies have shown that spatial skills can be improved and are linked to mathematical reasoning. However, there are few studies that have evaluated the effect of Mental Rotation (MR) training on mathematical performance in children aged 6–8 years. One of the studies has shown a transfer towards a mathematical task, while the other has failed to demonstrate it. The present study investigated with children in 2nd grade of Primary Education the effect of training on MR, with 450 trials distributed across three sessions, as well as on mathematical competence. The results showed an improvement in this spatial skill in the experimental group in relation to the control (η p 2 = 0.10). There were no differences between sexes in MR before training, and the increase was significantly higher in boys, when intelligence was controlled. Without controlling intelligence, both sexes improved at the same rate. These results are consistent with two parallel studies that were carried out with preschool and secondary school students. The MR training did not produce any improvement in mathe- matical ability. 1. Introduction Several studies carried out over the past 50 years state that spatial reasoning is key to success in the so-called STEM disciplines – Sciences, Technology, Engineering and Mathematics – (Shea, Lubinski, & Benbow, 2001; Wai, Lubinski, & Benbow, 2009). Moreover, spatial reasoning is very important in different everyday tasks, such as driving, following instructions to assemble a piece of furniture, or orientating in a given space. In Uttal et al.'s (2013) meta-analysis, the magnitude, durability, and transfer of spatial reasoning training were assessed through 206 studies. The results indicated that this type of reasoning is malleable through training, both in men and women, and at different points in the evo- lutionary cycle (children and adults). Most studies that have addressed this type of training have been conducted on the adult population (as can be seen in Uttal et al.'s meta analysis, 2013), with those performed on children or adolescents being less frequent. Spatial reasoning in children is essential; in fact, it is so closely linked to the development of numerical comprehension that early spatial intelligence predicts a child's performance in mathematics (Newcombe, Levine, & Mix, 2015; Verdine, Golinkoff, Hirsh-Pasek, & Newcombe, 2017). For example, Zhang et al. (2014) have noted that young children who are better at spatial visualization (i.e., detecting multiple spatial forms or shapes, rotating or manipulating them in the imagination, and matching them to form a complete shape) develop stronger arithmetic skills in Primary school. In some way, this could also be determinant for the child's performance in later stages, in the sense that middle school students (eighth-grade students; 13–15 years old) with better mental rotation (MR) abilities are more likely to suc- ceed in science (Ganley, Vasilyeva, & Dulaney, 2014). Mental Rotation (hereinafter, MR), one of the spatial skills that has received most attention from a psychometric and cognitive point of view, implies being able to mentally manipulate bidimensional and tridimensional stimuli swiftly and accurately (Linn & Petersen, 1985). The relationship that this ability has with academic performance, for example, in tasks involving the representation of different per- spectives in technical drawing, the resolution of geometry problems or the understanding of molecular structures, leads this ability to acquire a great interest within the STEM disciplines. https://doi.org/10.1016/j.lindif.2019.01.001 Received 11 April 2017; Received in revised form 31 December 2018; Accepted 2 January 2019 ⁎ Corresponding author at: Departamento Psicología Básica I, Facultad de Psicología, UNED, Juan del Rosal, 10, 28040 Madrid, Spain. E-mail address: mjcontreras@psi.uned.es (M.J. Contreras). Learning and Individual Differences 70 (2019) 1–11 1041-6080/ © 2019 Elsevier Inc. All rights reserved. T