Ation. The results suggest substantial genetic influence unique to spatial ability as a whole, but indicate that dissociations between the more specific constructs (rotation and visualisation, in 2D and 3D) disappear when tested under identical conditions: they are highly correlated phenotypically, perfectly correlated genetically (indicating that the same genetic influences underpin performance), and are related similarly to other abilities. This has important implications for the structure of spatial ability, suggesting that the proliferation of apparent subdomains may sometimes reflect idiosyncratic tasks rather than meaningful dissociations. Spatial ability is one of the most widely-studied domains of cognitive ability, yet there is little consensus as to its nature or structure. It has been found to be a strong predictor of important outcomes, such as science, technology, engineering and maths (STEM) performance1, but its usefulness in this regard is limited by the lack of understanding about its basic architecture. Broadly defined, the spatial domain comprises the processes LDN193189 web involved in perceiving, memorising and manipulating mental representations of visual scenes2, including two-dimensional (2D) and three-dimensional (3D) objects1,3 and the relationships between them4. Putative processes, categories and sub-domains uch as visualisation5, spatial orientation6, mental rotation7, spatial relations6 and many others ave proliferated in the literature, often with overlapping definitions, to the extent that the term “spatial ability” itself is difficult even to define with precision8,9. A great many spatial tests have been developed and are commonly used, with varying intercorrelations among them, and several theories have been proposed to describe the multifactorial structure suggested by these relationships4,9,10. Two major putative sub-domains (among many others) are “mental rotation” and “visualisation”. Definitions vary, but mental rotation involves rotating mental models of objects into different orientations, and visualisation describes various complex mental manipulations of spatial information, including identifying hidden or partially occluded objects from incomplete information11. Theories differ as to the nature of these abilities and the relationship between them, with some proposing that they represent distinct sub-domains of spatial ability5, while others suggest that visualisation is a major sub-domain, of which mental rotation is merely a component or exemplar9. Similarly, investigating the effects of the dimensionality of stimuli has led to contradictoryMedical Research Council Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, SIS3MedChemExpress SIS3 Psychology Neuroscience, King’s College London, London, United Kingdom. 2Goldsmiths, University of London, New Cross, London, United Kingdom. 3University of Sussex, Sussex House, Falmer, Brighton, United Kingdom. 4Tomsk State University, Tomsk, Russia. Correspondence and requests for materials should be addressed to N.G.S. (email: [email protected])Scientific RepoRts | 6:30545 | DOI: 10.1038/srepwww.nature.com/scientificreports/results, with some studies3,12 finding differences between the processing of 2D and 3D stimuli, and other results9,13 suggesting otherwise. One possible explanation for some of the inconsistent findings in the literature is that the available tests may not be “pure”, in the sense that their items may conflate multiple cognitive pro.Ation. The results suggest substantial genetic influence unique to spatial ability as a whole, but indicate that dissociations between the more specific constructs (rotation and visualisation, in 2D and 3D) disappear when tested under identical conditions: they are highly correlated phenotypically, perfectly correlated genetically (indicating that the same genetic influences underpin performance), and are related similarly to other abilities. This has important implications for the structure of spatial ability, suggesting that the proliferation of apparent subdomains may sometimes reflect idiosyncratic tasks rather than meaningful dissociations. Spatial ability is one of the most widely-studied domains of cognitive ability, yet there is little consensus as to its nature or structure. It has been found to be a strong predictor of important outcomes, such as science, technology, engineering and maths (STEM) performance1, but its usefulness in this regard is limited by the lack of understanding about its basic architecture. Broadly defined, the spatial domain comprises the processes involved in perceiving, memorising and manipulating mental representations of visual scenes2, including two-dimensional (2D) and three-dimensional (3D) objects1,3 and the relationships between them4. Putative processes, categories and sub-domains uch as visualisation5, spatial orientation6, mental rotation7, spatial relations6 and many others ave proliferated in the literature, often with overlapping definitions, to the extent that the term “spatial ability” itself is difficult even to define with precision8,9. A great many spatial tests have been developed and are commonly used, with varying intercorrelations among them, and several theories have been proposed to describe the multifactorial structure suggested by these relationships4,9,10. Two major putative sub-domains (among many others) are “mental rotation” and “visualisation”. Definitions vary, but mental rotation involves rotating mental models of objects into different orientations, and visualisation describes various complex mental manipulations of spatial information, including identifying hidden or partially occluded objects from incomplete information11. Theories differ as to the nature of these abilities and the relationship between them, with some proposing that they represent distinct sub-domains of spatial ability5, while others suggest that visualisation is a major sub-domain, of which mental rotation is merely a component or exemplar9. Similarly, investigating the effects of the dimensionality of stimuli has led to contradictoryMedical Research Council Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, Psychology Neuroscience, King’s College London, London, United Kingdom. 2Goldsmiths, University of London, New Cross, London, United Kingdom. 3University of Sussex, Sussex House, Falmer, Brighton, United Kingdom. 4Tomsk State University, Tomsk, Russia. Correspondence and requests for materials should be addressed to N.G.S. (email: [email protected])Scientific RepoRts | 6:30545 | DOI: 10.1038/srepwww.nature.com/scientificreports/results, with some studies3,12 finding differences between the processing of 2D and 3D stimuli, and other results9,13 suggesting otherwise. One possible explanation for some of the inconsistent findings in the literature is that the available tests may not be “pure”, in the sense that their items may conflate multiple cognitive pro.