BioMed Central Page 1 of 8 (page number not for citation purposes) Behavioral and Brain Functions Open Access Research Decision making: rational or hedonic? Michel Cabanac* and Marie-Claude Bonniot-Cabanac Address: Department of Physiology, Faculty of Medicine, Laval University, Canada Email: Michel Cabanac* - michel.cabanac@phs.ulaval.ca Marie-Claude Bonniot-Cabanac - marie-claude.bonniot@ap.ulaval.ca * Corresponding author Abstract Three experiments studied the hedonicity of decision making. Participants rated their pleasure/ displeasure while reading item-sentences describing political and social problems followed by different decisions (Questionnaire 1). Questionnaire 2 was multiple-choice, grouping the items from Questionnaire 1. In Experiment 1, participants answered Questionnaire 2 rapidly or slowly. Both groups selected what they had rated as pleasant, but the 'leisurely' group maximized pleasure less. In Experiment 2, participants selected the most rational responses. The selected behaviors were pleasant but less than spontaneous behaviors. In Experiment 3, Questionnaire 2 was presented once with items grouped by theme, and once with items shuffled. Participants maximized the pleasure of their decisions, but the items selected on Questionnaires 2 were different when presented in different order. All groups maximized pleasure equally in their decisions. These results support that decisions are made predominantly in the hedonic dimension of consciousness. Background "Gut reaction" is efficacious" [1] For several decades, research in judgment and decision making has examined behavioral violations of rational choice theory [2,3]. For example, Baron showed convinc- ingly that many decisions appear to be irrational, as if decision-makers were indifferent to the consequences of their decisions [2]. Erev and Roth showed that decisions in gambling situations are made at low rationality, the gamblers' aim being to maximize reinforcement [4,5]. Berridge concluded that a rational decision is a decision that maximizes utility (with all the ambiguity contained in the word utility) [6]. Epstein's [7] proposal of a "dual-process" in decision making casts some light on that experiential" rational, abstract, and analytical treatment of the available infor- mation, and a second one, "experiential" and "emotion- ally driven". According to Epstein, both systems fulfill different functions. Loewenstein and co-workers [8] pro- posed also an alternative theoretical perspective, the risk- as-feelings hypothesis, that highlights the role of affect experienced at the moment of decision making. Similar views were expressed by Reyna & Farley [9]: "Risky deci- sions making can be roughly divided into a) those [...] that adhere to a rational behavioral decision-making framework [...] and b) those that emphasize non-deliber- ative reaction to the perceived gists or prototypes in the immediate decision environment. " The experiential sys- tem is present in animals and leads to effortless decisions. The analytical system emerged more recently in humans with the development of language. The present experi- ments were developed in the same framework, exploring hedonicity pitted against several variables involved in Published: 11 September 2007 Behavioral and Brain Functions 2007, 3:45 doi:10.1186/1744-9081-3-45 Received: 18 May 2007 Accepted: 11 September 2007 This article is available from: http://www.behavioralandbrainfunctions.com/content/3/1/45 �� 2007 Cabanac and Bonniot-Cabanac licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Behavioral and Brain Functions 2007, 3:45 http://www.behavioralandbrainfunctions.com/content/3/1/45 Page 2 of 8 (page number not for citation purposes) decision making: time available for decision making, rationality, and recognition. Maximization of hedonic experience is a universal mech- anism inherited by humans to motivate behavior [10] and makes pre-rational decisions [11-13]. Emotion interferes powerfully with decision making [14]. Mellers recently proposed an account of emotional experiences associated with the outcomes of decisions called "decision affect the- ory." It incorporates utilities, expectations, and counter- factual comparisons into hedonic responses. That is, people choose the risky options for which they expect to feel better on average [15,16]. Conversely, positive moods may increase sensitivity to the meaning-relevance of a sit- uation [17]. Price et al. also have proposed a commonality between cognitive processes underlying emotions and choice [18]. Such views are similar to Cabanac's notion of pleasure being the "common currency," if one accepts that emotion is basically an intense hedonic experience [19]. Slovic and co-workers reached a similar conclusion, using the terms affectivity and affect to qualify that something is good or bad [20]. Optimization of everyday life decisions is similar in per- ception and memory processes [21], which suggests that the laws of mental optimization are similar and possibly universal. In previous experiments we have studied the place of pleasure in decisions made in various domains [22,23], yet, it was noticeable that never, in any of our pre- vious studies where we explored decisions in various fields in relation to hedonic experience did any partici- pant choose 100% responses providing pleasure. Thus, other factors must enter, of course, into account besides hedonicity. A recent review suggested that both rational and intuitive decision making processes are likely to play an important role in ethical decision making [24]. "A vast area exists between irrational and rational that can be called arational" [25]. In the present paper we examined the hypothesis that such an arational process is actually hedonic. We studied the influence of hedonicity in three separate experiments. The aim of the present work was double: first, to verify whether previous experimental data showing the preeminent role of pleasure in decision mak- ing, could be confirmed while the previous experimental protocols were modified, and second, an attempt to falsify our working paradigm by removing the tautology involved in studies where participants rate hedonically various items, then select those they prefer. Both aims were tackled in the following experiments. Methods Participants One hundred and twenty persons volunteered to partici- pate anonymously in the study. They were recruited at random on campus and in supermarkets. The only crite- rion for selection of volunteers was a progressive attempt to match, as well as possible, sex and age ratios in Experi- ment 1, and then less so in Experiments 2, and 3. Each person participated individually in a private interview. The duration for answering Questionnaires 1 and 2 (below) were timed. The only personal data recorded were participants' age and sex. Laval University Committee for the Ethics of Research approved the study. Questionnaires The general principle consisted in presenting two ques- tionnaires dealing with political and social problems. Because Grammar, Mathematics, Aggressiveness and Eth- ics had been studied in our previous studies, we explored here a new field, politics. There were 10 general topics: Irak war, Globalisation, Immigration, Family, Homosexu- ality, Abortion, Genetically Modified Organisms (GM Foods), North Korea, Palestine and Israel, and Cuba (see Additional file 1). Each of the general themes was pre- sented five times in a randomized order with each time a different solution to the political/social problem, which resulted in 50 items. The five possible solutions offered on each theme tried to cover a broad spectrum of decisions from staid conservative to extreme liberal. In Questionnaire 1, the 50 items were presented one after the other. The participants were invited to read carefully the first item, then write down on an answer sheet the amount of pleasure or displeasure evoked in them by that item pleasure and displeasure were considered as belong- ing to the same dimension [11]. The quantitative rating would be positive for pleasure, negative for displeasure, and zero for indifference (or for "I don't know"). The amplitude of the scale was left to the participants in order to let them use a scale with which they would feel at ease. Some chose from -5 to +5, others -10 to +10, or -20 to +20, etc. Such a liberty was given because results would be compared within each participant's results. In Questionnaire 2, the 50 items of Questionnaire 1 were presented grouped by five items on the same theme (see Additional file 1). This resulted in a multiple-choice Examination type with 10 entries, each containing all the 5 items on the same theme. The participants read the 5 items of the given entry and wrote on a new answer sheet which political solution they would decide to choose, in case were they in an executive position allowing decision to be adopted. Any mention of hedonicity was carefully avoided. Then the participants went to entry 2, then 3, up to the 10th and made the same decisions. Data analysis Once the data had been collected for all participants, the ratings on Questionnaire 1 and decisions on Question- naire 2 were compared as follows: because all participants