How Do People Know How to Throw a Ball? Underhand Throwing by Congenitally Totally Blind and Blindfolded Sighted Adults
Persons who are blind participate in a wide number of sports, ranging from the various competitions in track and field, to goal ball and baseball. How is it, we asked, that persons know how to throw a ball? Learning through observing others and through instruction are main candidates, but we hypothesized there was an intrinsic basis to throwing. To test this hypothesis, congenitally totally blind adults and blindfolded sighted adults were asked to throw balls that varied in weight to targets that varied in distance. The congenitally totally blind adults had never observed someone else throw a ball and they received no instruction about how to throw. The results show there is both an intrinsic and learned basis for throwing. The throws and throw distances of the blind participants were correlated to the target distance, showing that they knew the fundamentals; the throws of the blindfolded sighted participants were even more coordinated and came much closer to the target, showing that observation and varying amounts of coaching also play a role.