Term of Award

Spring 2014

Degree Name

Master of Science in Experimental Psychology (M.S.)

Document Type and Release Option

Thesis (open access)


Department of Psychology

Committee Chair

Karen Z. Naufel

Committee Member 1

Lawrence Locker

Committee Member 2

Kent D. Bodily


Decisions to either to prepare or not prepare for weather threats involve uncertainty. Uncertainty in decision making often involves the potential for making either a false positive (preparing for a storm that never arrives) or a false negative error (not preparing for a real storm). Error Management Theory (EMT; Haselton & Buss, 2000) posits that, depending on the uncertain context, people select a decision-making strategy that favors one error over the other. Related to weather, research has shown that people prefer a false positive, or an overestimation (Joslyn et al., 2011). Particularly, this overestimation appears when people receive severe information prior to making a judgment. Thus, the present study tested whether or not the quality of severity influenced people to select a bias towards a false positive error. In two studies, participants made judgments about Friday’s weather after viewing nine different sequences of two forecasts (sunny, cloudy, or stormy) from early in the week (Study 1) or after viewing weather forecasts from Monday and Wednesday (Study 2). In both studies, participants tended to base their judgments on the second forecast. The interpretation of this pattern, however, differs between the two studies based on anchor-type. In Study 1, bias toward the second forecast was the best available, least biased decision-making strategy. In Study 2, however, bias toward the second forecast was irrational because Wednesday’s weather is not informative for Friday’s weather. Thus, Study 2 demonstrated an anchoring-like bias.