| Heaviness perception involves a misperception of weight known, since the 19th century, as the Size-Weight Illusion ^1^. The larger of two objects of equal mass is reported to be lighter than the smaller when they are lifted. The illusion has been found to be reliable and robust. It persists even when people know that the masses are equal and handle objects properly ^2^. It has been exhibited by children of only 2 years of age ^3,4^. All this suggests that the effect might be intrinsic to humans. Although different hypotheses have been advanced to account for the illusion over the 100+ years it has been studied ^5-11^, its origin remains unknown. More recently, people's perception of optimal objects for long distance throwing was found to exhibit a... |
