Discounting and the role of the relationship between causes

This research investigates how the relation between two causes (i.e. whether they co-occur or not) affects the likelihood to discount one of them. In two experiments, two causes were either system- atically paired together (positive relation), were paired with many other causes (independent relation), or were never paired together (negative relation). The results indicate that discounting of one of the causes (target cause) depends on the relation with the other cause (alternative cause) and the order in which the alternative cause was presented and produced the outcome alone. If information on the independent outcome of the alternative cause came prior to the joint outcome of the alternative and target cause (forward order), then discounting of the target cause occurred regardless of the relation between the two causes. If, however, information on the independent outcome of the alternative cause came after the joint outcome of the alternative and target cause (backward order), then discounting of the target cause occurred mainly when there was a positive or negative relation between the causes, but not when there was an independent relation. The degree of backward discounting given a positive or negative relation was largely identical. These results are consistent with the retrospective revaluation hypothesis of Dickinson and Burke (1996) and shed new light on the role of the relation between causes on discounting.