University of Iowa
Department of Psychology
Personality and Social Psychology
C5 Seashore Hall
Iowa City, IA 52242
I am interested in the factors that influence everyday judgment and decision making. For example, people estimate the length of the Mississippi River to be longer when they first compare the length to 5,000 miles as compared to people who first compare the length to 200 miles. The comparison value is irrelevant to the final judgment, but people tend to be influenced by this value. Situations where people integrate irrelevant information into the decisions they make are quite common. The research I do investigates situations where this might happen in an attempt to describe and explain judgment and decision making behavior.
Specifically, my areas of interest include: wishful thinking, comparative optimism (and pessimism), the group size effect, anchoring and adjustment, the dud-alternative effect, perceptions of risk and likelihood. [more to come soon]
Windschitl, P.D., Rose, J.P., Stalkfleet, M.T., & Smith, A.R. (2008) Are people excessive or judicious in their egocentrism? A modeling approach to understanding bias and accuracy in people’s optimism within competitive contexts. Journal of Personality and Social Psychology, 95, 253-273. [Abstract] [Full Article]
People are often egocentric when judging their likelihood of success in competitions, leading to overoptimism about winning when circumstances are generally easy for competitors but overpessimism when the circumstances are difficult. Yet, egocentrism might be grounded in a rational tendency to favor highly reliable information (about the self) more so than less reliable information (about others). A general theory of probability, called extended support theory (EST) was used to conceptualize and assess the role of egocentrism and its consequences for the accuracy of people’s optimism in three competitions (Studies 1-3, respectively). Also, instructions were manipulated to test whether people who were urged to avoid egocentrism would show improved or worsened accuracy in their likelihood judgments. Egocentrism was found to have a potentially helpful effect on one form of accuracy, but people generally showed too much egocentrism. Debias instructions improved one form of accuracy but had no impact on another. The advantages of using the EST framework for studying optimism and other types of judgments (e.g., comparative ability judgments) are discussed.
Price, P.C., Smith, A.R., & Lench, H.C. (2006). The effect of target group size on risk judgments and comparative optimism: The more the riskier. Journal of Personality and Social Psychology, 90, 382-398. [Abstract] [Full Article]
In 5 experiments, college students exhibited a group size effect on risk judgments. As the number of individuals in a target group increased, so did participants’ judgments of the risk of the average member of the group for a variety of negative life events. This happened regardless of whether the stimuli consisted of photographs of real peers or stick-figure representations of peers. As a result, the degree to which participants exhibited comparative optimism (i.e., judged themselves to be at lower risk than their peers) also increased as the size of the comparison group increased. These results suggest that the typical comparative optimism effect reported so often in the literature might be, at least in part, a group size effect. Additional results include a group size effect on judgments of the likelihood that the average group member will experience positive and neutral events and a group size effect on perceptual judgments of the heights of stick figures. These latter results, in particular, support the existence of a simple, general cognitive mechanism that integrates stimulus numerosity into quantitative judgments about that stimulus.
Windschitl, P.D., Smith, A.R., Rose, J.P., & Krizan, Z. (under review). The Desirability Bias in Predictions: Going Optimistic Without Leaving Realism [Abstract]
Does desire for an outcome inflate optimism? That is, are people prone to a desirability bias? Previous experiments have produced mixed results, with the bulk of supportive findings coming from the marked-card paradigm, in which people make discrete predictions about desirable or undesirable cards being drawn from decks. Experiment 1 of the present series demonstrated a desirability bias using an improved version of this paradigm that rules out two artifactual explanations for previous findings. Experiments 2-4 examined how the bias might extend beyond the typical marked-card paradigm to cases in which the outcome is nonstochastic (trivia outcomes) and to cases in which likelihood judgments rather than discrete predictions are solicited. The findings provided support for a new biased-guessing account, which assumes that people are often realistic in their likelihood assessments, but when making a subjectively arbitrary prediction (a guess), they will tend to guess in a desired direction.
Smith, A.R., Windschitl, P.D., & Rose, J. Understanding Referent-Dependent Assessments by Comparing Biases in Probability and Comparative Judgments [Summary]
Research on social-comparative judgments, comparative-optimism judgments, and more generic probability judgments has revealed a set of biases that appear to be interrelated and might (or might not) be explained by similar accounts. For example, above-average effects observed in comparative judgment and subadditivity effects observed in probability judgments clearly have some structural/conceptual relationships. Both comparative and probability judgments require an assessment of the target and referents, however, no previous studies have directly compared these two types of referent-dependent judgments. The present study tested the role of focalism, unpacking, and other accounts by having participants make either comparative or probability judgments that required them to evaluate a focal item (e.g., a specific high-calorie food) in relation to sets of 1, 4 or 9 referent items (e.g., other high-calorie foods). Initial analyses provide support for the predictions of the focalism account as well as partial support for Support Theory across the two judgment types. We provide an explanation for these findings as well as integrate previous research on both comparative and probability judgments.
Smith, A.R., Windschitl, P.D., & Bruchmann, K.I. Knowledge and Cognitive Load Moderate the Influence of Incentives and Forewarning on Adjustment from Irrelevant Anchors. [Summary]
Soon.
Smith, A.R. & Windschitl, P.D. Wishful Thinking in Polychotomous Decisions [Summary]
Wishful thinking (an increase in the perceived likelihood of an event because of a desire for that event to occur) is widely accepted by the general population, yet relatively understudied by the scientific community (for a review of wishful thinking, see Krizan & Windschitl, 2007). The majority of wishful thinking studies have examined dichotomous decision tasks (i.e., tasks where one of two options will occur). However, in real world decision tasks, there are often numerous possible outcomes. In this study, wishful thinking is examined in situations where participants make decisions with more than two possible outcomes.
Smith, A.R., Windschitl, P.D., & Price, P.C. The Effect of Group Size on Non-Social Judgments. [Summary]
The group size effect has been demonstrated when people make risk judgments about the average member of a group (Price, Smith, & Lench, 2006). For example, the average member of a group of 15 is perceived as more likely to get cancer than the average member of a group of 10. Although the group size effect has only been observed when making judgments about groups of people, it may occur when evaluating non-social items as well. Specifically, the average rating of a group of 10 movies may be perceived as being higher than the average rating of a group of 5 movies.
Smith, A.R., Lee, S.W., & Price, P.C.When Large Companies are Better (and Worse) than Small Companies: The Effect of Group Size in Managerial Decisions. [Summary]
Price (2001) found that the average member of a company with 9 workers was perceived to have a higher heart attack risk than than the average member of a company with 4 employees. It is likely that the group size effect will generalize to judgments made about areas other than heart attack risk. Therefore, people should view the output of the average member of a large company to exceed that of the average member of a small company. Similarly, a large company should be perceived to commit more work related accidents per worker than a small company. Therefore, a large company will be evaluated as both better (when judging positive factors) and worse (when judging negative factors) than a small company.
Smith, A.R. & Windschitl, P.D. The Dud-Alternative Effect in Competitive Situations. [Summary]
The dud-alternative effect occurs when the introduction of an outcome with a low likelihood of occuring increases confidene in the focal outcome. For example, adding raffle contestants who hold only 1 or 2 tickets (i.e., they have a very small chance of winning the raffle) tends to increase people's confidence that they will win the raffle. This occurs despite the fact that their objective chance of winning decreases whenever additional contestants are added. This research will extend this research into competitive situations such as basketball tournaments.
