Distributed decision making under uncertainty

Experiments are described that studied how people make team decisions under uncertainty when they second-guess their partner. Subjects were presented with a sequence of targets. They were told that they should shoot at light-weight targets and that their partner would shoot at heavy ones. Target weight was ambiguous, but could be estimated from target size and color. An optimal decision strategy is to shoot if and only if the target´s estimated weight is below a shoot/no shoot threshold. Though the subjects´ behavior qualitatively resembled what would be expected if they were following the optimal decision strategy, subjects did not seem to make their decisions this way. Rather than using a shoot/no shoot threshold, they instead based their decisions on their guesses of what their partners would do. When a partner behaved differently from normal, subjects assumed that he/she was estimating weight differently rather than following different rules. Subjects attempted to guess what their partners would do even for partners who shot at random