Adult participants report expecting darker objects to be heavier in weight and brighter objects to be lighter in weight (Payne, 1958; Plack & Shick, 1976; Walker, Francis & Walker, 2010; Wright 1962). Although there is evidence that young infants appreciate crossmodal correspondences between pitch and height, and sharpness, there is no evidence to date that infants appreciate the correspondence between brightness and weight (Walker, Bremner, Mason, Spring, Mattock, Slater, & Johnson, 2010; Walker, Bremner, Lunghi, Dolscheid, Barba, & Simion, 2018). The objective of the current thesis was to understand more about the correspondence between brightness and weight by examining the situations in which it is revealed and the age at which it emerges. In doing so, the intention was to uncover more information about the nature of the correspondence and its potential origins. Using verbal reports, Experiments 1 and 3 provided further evidence of a brightness-weight and material-weight correspondence in adult participants. By examining whether the correspondence is acted upon spontaneously, Experiments 2 and 4 revealed early evidence that adults selectively prepare for objects based on brightness and material. The potential reasons for the selective preparation are discussed in detail. In Experiments 5 and 6, infants’ appreciation of the brightness-weight and material-weight correspondences were explored. Whilst the studies revealed no evidence for appreciation of the brightness-weight correspondence, Experiment 6 provided substantial evidence suggesting that infants selectively prepare for objects based on material. The implications of these findings, and the potential inferences that can be made about the nature and origins of the brightness-weight correspondence are discussed.