Perception of relative throw-ability.

Bingham et al. (J Exp Psychol Hum Percept Perform 15(3):507-528, 1989) showed that skilled throwers can perceive optimal objects for throwing to a maximum distance. Zhu and Bingham (J Exp Psychol Hum Percept Perform 34(4):929, 2008, 36(4):862-875, 2010) replicated this finding and then showed that felt heaviness is used to perceive this affordance (see also Zhu and Bingham in Evol Hum Behav 32(4):288-293, 2011; Zhu et al. in Exp Brain Res 224(2):221-231, 2013). Throwers pick the best weight for spherical projectiles in each graspable size. Bingham et al. (J Exp Psychol Hum Percept Perform 15(3):507-528, 1989) speculated that relative throw-ability might be perceptible. This would mean that the ordering of distances achieved by maximum effort throws of different objects could be judged. This affordance property is not the same as optimal throw-ability, because it requires all projectiles to be evaluated relative to one another with respect to ordinally scaled distances, not just a discrete optimum. We now used a magnitude estimation task to test this hypothesis, comparing the resultant ordering with that exhibited by distances of throws in previous studies. The findings show that participants were able to perform the perceptual task. However, discrimination among objects of different weight within a size was better than between sizes. The implications of these results for understanding of the information used to perform this task are discussed.