Origin
Spatial reasoning is the ability to generate, retain and mentally transform visual images. Thurstone identified "Space" as one of his primary mental abilities, and the Cattell-Horn-Carroll model places it within visual processing (Gv).
The classic experimental demonstration is Shepard and Metzler's (1971) mental-rotation studies, in which response time rises in proportion to the angle a figure must be rotated.
Structure
Common tasks include mental rotation, paper folding, block counting, cross-section visualisation and embedded-figure identification. The Purdue Spatial Visualization Test and the perceptual-reasoning subtests of the Wechsler scales are widely used examples.
The defining feature is manipulating spatial relationships without physically moving objects.
Psychometric standing
Spatial ability is a distinct, replicable factor and a meaningful predictor of achievement and attainment in science, technology, engineering and mathematics, even after accounting for verbal and mathematical ability (Wai, Lubinski & Benbow, 2009). It responds to practice, so scores reflect current visualisation skill rather than an immutable ceiling.