Historically, the existence of a size-weight illusion has led to the conclusion that perceptions of size and weight are not independent. A dependence of perceived heaviness on physical volume (perceptual separability), however, is different from a dependence on perceived volume (perceptual independence). Three experiments were conducted to evaluate perceptual independence. The relations between perceived size and weight and physical size and mass were evaluated in Experiment 1. Perceived weight, length, and width were structured only by the corresponding physical variables, whereas variations in volume were not separable from variations in mass. F. G. Ashby and J. T. Townsend's (1986) test for perceptual independence was applied in Experiment 2. Perceived weight was independent of perceived length and volume. Experiment 3 used a magnitude estimation paradigm to investigate the extent to which information-perception relations could be related to the observed patterns of separability and independence. In the course of many common activities (such as using eating utensils, various tools, or athletic equipment), one is able to perceive various properties of objects through grasping and lifting. Such perceptions are often achieved by means of the muscle's sensory capabilities-a sensibility known classically as the muscle-sense and more recently as kinesthesia. From the earliest investigations of the musclesense, two kinds of perceptions have been identified. The first was the perception of weight (Weber, 1834 (Weber, /1978 . Weber demonstrated that observers were better at discriminating among the masses of objects when they were actively lifted rather than passively rested in the hand. This demonstration indicated that observers used the sensory capabilities of their muscles in generating a perception of weight. A second perception attributable to the muscle-sense was the perception of an object's length. Hoisington (1920) noted that individuals were remarkably good at judging the length of an object that they could hold but not see. Because observers only held these objects and did not run their hands along the lengths of the stimuli, this perception of size is also achieved using the muscle's sensory capabilities.
Amazeen REF also showed that a dependence of perceived heaviness relies on a dependence on perceived volume (perceptual independence).
Perceptual independence of size and weight by dynamic touch.
Journal of experimental psychology. Human perception and performance
Journal of experimental psychology. Human perception and performance
Psychology Medicine