Out of sight, out of mind? How discarded items shape environmental judgments

Consumers often inspect products before making purchase decisions. Some items are selected for their shopping baskets, while others are discarded. Can discarded products influence how the selected set is perceived? We examined this question across two experiments. Participants viewed sequences of grocery products, some included in the shopping basket and some discarded, and were asked to provide a summative estimate of the included set's environmental friendliness after presentation. In Experiment 1, participants had to remember which items to consider for the upcoming judgment, as each item disappeared after presentation. In Experiment 2, each item remained visible after presentation. Discarded green (environmentally friendly) items produced a downshift in perceived environmental friendliness of the included set of items in Experiment 1 (a contrast effect), but an upshift in Experiment 2 (an assimilation effect). Correspondingly, discarded red (environmentally harmful) items produced an upshift in Experiment 1 and a downshift in Experiment 2. These findings show that discarded items can shift judgments of environmental friendliness, but that the direction of this effect depends on whether discarded items are mentally excluded or perceptually integrated with the remaining set.