Singleton bias and lexicographic preferences among equally valued alternatives

Two experiments examined a form of singleton bias deducible from lexicographic choice and Tversky’s theory of elimination by aspects. In Experiment 1, 100 decision makers who chose from a set of job applicants defined by equal numbers of equally important qualifications tended to ignore the singleton defined by possession of a relevant attribute but tended to rank-order the attributes as predicted by lexicographic choice theory and showed various forms of singleton bias. In Experiment 2, 100 decision makers who chose from sets of unspecified alternatives, universities, and houses/apartments defined by attributes that they had individually rated as equally important ignored the attribute-defined singleton in every alternative set but manifested a different singleton bias in favor of the middle option of the on-screen display.