Probabilistic inferences under emotional stress

Probabilistic inferences under emotional stress Szymon Wichary (swichary@swps.edu.pl) Interdisciplinary Center for Applied Cognitive Studies Warsaw School of Social Sciences and Humanities Ul. Chodakowska 19/31, 03-815 Warsaw, Poland University of Basel, Department of Psychology Missionsstrasse 62a, 4055, Basel, Switzerland Jorg Rieskamp (joerg.rieskamp@unibas.ch) University of Basel, Department of Psychology Missionsstrasse 62a, 4055, Basel, Switzerland Abstract Many models of cognition neglect emotional states that could affect individuals‘ cognitive processes. The present study explores the effect of emotional stress on people‘s cognitive processes when making probabilistic inferences. It was hypothesized that emotional stress reduces cognitive capacity, leading to the selection of simple inference strategies. Emotional stress was induced with highly arousing negative pictures briefly presented to participants before they made an inference. Emotional stress influenced the selectivity of participants‘ information search. Emotionally stressed individuals relied on the importance of the cues to a greater extent than the nonstressed participants. They also spent less time on the least important information. Moreover, the proportion of participants‘ choices consistent with a simple lexicographic heuristic was higher for the emotionally stressed participants than for the nonstressed participants. The results suggest that people respond adaptively to emotional stress by selecting heuristics that require less information and fewer cognitive operations. Keywords: emotional stress; information search; inference strategies. Affect and strategy use Many theories of cognition treat the human mind as a cold information processor that always performs under the same conditions. In contrast, humans make decisions in varying emotional states (e.g., Schwarz, 2000). Do the cognitive processes underlying people‘s inferences change when they are emotionally aroused? This is the central question of the present article. Decision making is influenced by affective states. Isen and Means (1983) showed that people in a mildly positive mood made decisions more quickly, analyzed less information, and therefore seemed to select simpler strategies for making decisions than people in neutral affective states. Luce, Bettman, and Payne (1997) showed that task-related negative emotions, induced by conflict among attributes, led to more extensive information search, but the search was at the same time more selective and more attribute based. The above studies employed rather mild manipulation of affect. A few other studies looked at more extreme affective states. Mano (1992) showed that participants under social stress (anticipated in-class presentation) employed simpler decision strategies and were more polarized in their decisions. Lewinsohn and Mano (1993) showed that more highly aroused participants, when performing multi-attribute choice tasks, acquired less information and acquired it in a more selective manner, ignoring more attributes than less aroused participants and focusing on the subjectively important attributes. They concluded that ―under conditions of extremely high arousal, the decision maker may shift to a very ‗thin‘ processing strategy and could be forced to oversimplify the decision process‖ (Lewinsohn & Mano, The above studies provide evidence that affect influences the selection of decision strategies. However, these studies did not examine directly which strategy was best in predicting participants‘ choices; instead, strategy selection was inferred from participants‘ information search behavior. The analysis of information search often does not allow an unequivocal identification of decision strategies, a problem that has been pointed out repeatedly (Luce et al., 1997; Rieskamp & Hoffrage, 2008). Therefore, we think it is important to extend the research on affect and strategy selection by studying participants‘ information search and their actual choices. Probabilistic inference In a probabilistic inference task, individuals make an inference about a criterion on the basis of several cues (e.g., Gigerenzer & Goldstein, 1996). For instance, one could infer which of two patients requires more urgent treatment on the basis of several cues such as respiration or heart rate. The cues are only probabilistically related to the criterion, so that a positive cue value makes a positive criterion (e.g., a more precarious physical status) only more likely. Probabilistic inferences require a relatively long sequence of cognitive operations that usually result from the application of cognitive strategies. Cognitive strategies The inference task described above can be solved with various inference strategies, like the lexicographic strategy,