Attraction comes from many sources. Attentional and comparative processes in decoy effects

The attraction effect emerges when adding a seemingly irrelevant option(decoy) to a binary choice shifts preference towardsa target option. This suggests that choice behaviour is dynamic, i.e., choice values are developed during deliberation, rather thanmanifesting some pre-existing preference set. Whereas several models of multialternative and multiattribute decision makingconsider dynamic choice processes as crucial to explain the attraction effect, empirically investigating the exact nature of suchprocesses requires complementing choice output with other data. In this study, we focused on asymmetrically dominateddecoys (i.e., decoys that are clearly dominated only by the target option) to examine the attentional and comparative processesresponsible for the attraction effect. Through an eye-tracker paradigm, we showed that the decoy option can affect subjects’preferences in two different and not mutually exclusive ways: by focusing the attention on the salient option and the dominanceattribute, and by increasing comparisons with the choice dominant pattern.Although conceptually and procedurally distinct,both pathways for decoy effects produce an increase in preferencesfor the target option, in line with attentional and dynamicmodels of decision making. Eye-tracking data provide further details to theverification of such models, by highlighting thecontext-dependent nature of attention and the development of similarity-driven competitive decisional processes.