TY - JOUR TI - Clarifying the role of an unavailable distractor in human multiattribute choice AU - Cao, Yinan AU - Tsetsos, Konstantinos A2 - Zhang, Hang A2 - Gold, Joshua I A2 - Busemeyer, Jerome VL - 11 PY - 2022 DA - 2022/12/06 SP - e83316 C1 - eLife 2022;11:e83316 DO - 10.7554/eLife.83316 UR - https://doi.org/10.7554/eLife.83316 AB - Decisions between two economic goods can be swayed by a third unavailable ‘decoy’ alternative, which does not compete for choice, notoriously violating the principles of rational choice theory. Although decoy effects typically depend on the decoy’s position in a multiattribute choice space, recent studies using risky prospects (i.e., varying in reward and probability) reported a novel ‘positive’ decoy effect operating on a single value dimension: the higher the ‘expected value’ (EV) of an unavailable (distractor) prospect was, the easier the discrimination between two available target prospects became, especially when their expected-value difference was small. Here, we show that this unidimensional distractor effect affords alternative interpretations: it occurred because the distractor’s EV covaried positively with the subjective utility difference between the two targets. Looking beyond this covariation, we report a modest ‘negative’ distractor effect operating on subjective utility, as well as classic multiattribute decoy effects. A normatively meaningful model (selective integration), in which subjective utilities are shaped by intra-attribute information distortion, reproduces the multiattribute decoy effects, and as an epiphenomenon, the negative unidimensional distractor effect. These findings clarify the modulatory role of an unavailable distracting option, shedding fresh light on the mechanisms that govern multiattribute decisions. KW - decision-making KW - multiattribute choice KW - risky choice KW - distractor effect KW - context effect KW - selective integration JF - eLife SN - 2050-084X PB - eLife Sciences Publications, Ltd ER -