We asked participants to make simple risky choices while we recorded their eye movements. We built a complete statistical model of the eye movements and found very little systematic variation in eye movements over the time course of a choice or across the different choices. The only exceptions were finding more (of the same) eye movements when choice options were similar, and an emerging gaze bias in which people looked more at the gamble they ultimately chose. These findings are inconsistent with prospect theory, the priority heuristic, or decision field theory. However, the eye movements made during a choice have a large relationship with the final choice, and this is mostly independent from the contribution of the actual attribute values in the choice options. That is, eye movements tell us not just about the processing of attribute values but also are independently associated with choice. The pattern is simple—people choose the gamble they look at more often, independently of the actual numbers they see—and this pattern is simpler than predicted by decision field theory, decision by sampling, and the parallel constraint satisfaction model. © 2015 The Authors. Journal of Behavioral Decision Making published by John Wiley & Sons Ltd.
We thank Lukasz Walasek for help in running the experiment and Hemant Passi for help in developing the clustering and Poisson regression approach. We thank Nathaniel Ashby, Jerome Busemeyer, Susann Fiedler, Mackenzie Glaholt, Andreas Glöckner, Daniel Navarro-Martinez, Jacob Orquin, Keith Rayner, and Christoph Ungemach, our anonymous reviewers, and the members of the Decision Research at Warwick collaboration for their very helpful comments and discussion. This work was supported by funding from the University of Essex Research Promotion Fund, Economic and Social Research Council grants ES/K002201/1 and ES/K004948/1, and Leverhulme grant RP2012-V-022. Raw data and R code are available from the authors and will be posted on publication.
- eye tracking
- decision under risk