Blunt impact as deterrent: human approach-avoidance behaviors and other stress responses studied within a paintball gaming context

Blunt impact munitions are often used by civilian law enforcement and in military operations on urban terrain (MOUT) missions to dissuade individuals and groups from approaching valued assets. The use of blunt munitions (rubber-ball or sponge) is predicated on their effectiveness as aversive stimuli; the effectiveness is weighed against the risk of serious injury or death. However, little empirical evidence supports effectiveness. Here, we use a paintball gaming context to study the effects of blunt impact on performance and approach behaviors. Volunteers individually traversed a course in which targets offer the opportunity to gain for accuracy. While completing the targeting task, subjects were bombarded with paintballs, which progressively became more numerous and the impact more intense as the subjects neared goal locations. Initial data suggest that over 30 blunt impacts by paintballs delivered at 280 ft/sec over 30 to 100 ft are insufficient to overcome intrinsic and extrinsic approach motivations or impair targeting or advance performance in an overwhelming majority of subjects. Our apparent ceiling effect was surprising. A sub-comparison of the few subjects who stopped the game before the end with those who did not suggests that personality factors influence the effectiveness of blunt impact as a deterrent. While paintballs differ from traditional blunt impact munitions on a number of physical characteristics, impact that was sufficient to repeatedly bruise volunteers was not an effective deterrent.