Felt heaviness is used to perceive the affordance for throwing but rotational inertia does not affect either

Bingham et al. discovered a perceptible affordance property, composed of a relation between object weight and size, used to select optimal objects for long-distance throwing. Subsequent research confirmed this finding, but disconfirmed a hypothesis formulated by Bingham et al. about the information used to perceive the affordance. Following this, Zhu and Bingham investigated the possibility that optimal objects for throwing are selected as having a particular felt heaviness. The results supported this hypothesis. Perceived heaviness exhibits the size-weight illusion: to be perceived as equally heavy, larger objects must weigh more than smaller ones. Amazeen and Turvey showed that heaviness perception is determined by rotational inertia. We investigated whether rotational inertia would determine both perceived heaviness and throw-ability when spherical objects were held in the hand and wielded about the wrist. We found again that a particular judged heaviness corresponded to judged throw-ability. However, rotational inertia was found to have no effect on either judgment, suggesting that rotational inertia does not determine perceived heaviness of spherical objects held in the hand, as it did for the weighted-rod-type objects used by Amazeen and Turvey.