Strategies for Evaluating Opinions: A Cross-Cultural Study - eScholarship

Strategies for Evaluating Opinions: A Cross-Cultural Study Hugo Mercier (hmercier@isc.cnrs.fr) Institut Jean Nicod, 1bis, Avenue Lowendal Paris, 75007 France Jean-Baptiste Van der Henst (vanderhenst@isc.cnrs.fr) Institut des Sciences Cognitives, 67, boulevard Pinel Bron, 69675 France Hiroshi Yama (yama@mail.kobe-c.ac.jp) School of Human Sciences, Kobe College, 4-1 Okadayama Nishinomiya, 662-8505 Japan Yayoi Kawasaki (yayoi@iris.dti.ne.jp) School of Human Sciences, Kobe College, 4-1 Okadayama Nishinomiya, 662-8505 Japan Kuniko Adachi (k-adachi@osa.att.ne.jp) School of Human Sciences, Kobe College, 4-1 Okadayama Nishinomiya, 662-8505 Japan psychologists, under the headings of persuasion and attitude change. Here we will restrain the investigations to simple instantiations of these categories, using numerical estimates and giving only limited cues that might allow differentiating the value of the different opinions. Numerical estimates allow a precise evaluation of the way the various opinions involved are taken into account in establishing a final estimate. Abstract This paper aims at checking the cross-cultural validity of well-know findings concerning the way people integrate communicated information. In a first experiment, a Japanese and a French population weighted the advices they were given in similar ways. In a second experiment, both populations showed some evidence of bias towards their own answer relative to an advice. In both experiments, participants were more prone to choose one of the possible answers than to average over them. By replicating what had been previously found only in Western populations, these findings contradict some cross-cultural predictions. Mechanisms used in evaluating opinions Introduction Should you take your umbrella when leaving for work this morning? The weather forecast is good, but these clouds look quite menacing. Should you sell your shares in TransGear Inc.? Some experts say they will rise, but others predict a sudden drop. In everyday life we often have to rely, at least in part, on the opinions of other people. However, more often than not, these opinions are not in full agreement with each other. They may even openly clash, or they can contradict something you already thought. To deal with all these cases, we must be able to assess the value of the different pieces of information at our disposal, perhaps to reject some of them, before making our decisions. This paper will focus on the cases in which only two opinions are involved. They can either both come from some other people and pertain to a matter that we have no knowledge of; or an opinion can be given by someone else and be compared to our own. Broadly construed, this kind of phenomena has been extensively studied by social Several mechanisms designed to deal with these situations have been proposed. The first is the weighting heuristic (Yaniv, 1997). It is used when the quantitative estimates given are accompanied by a range of certainty. For example, one might predict that the chances that it rains tomorrow are of 50%, and give a range of 40 to 60%. Since it has been observed that confidence is correlated with accuracy (see Yaniv, Yates, & Smith, 1991), it is possible to use the size of the interval as a clue to the accuracy of the estimate. This is what the weighting heuristic does: it weights the different estimates by the relative size of the related interval: the wider the interval of an estimate, the smaller its weight. Other mechanisms are involved when one’s own opinion is involved in the process. In this case, the more robust finding is the self-other effect: it is a general bias to discount the other person’s opinion and to stick with one’s initial estimate (Harvey & Fischer, 1997; Lim & O'Connor, 1995; Yaniv, 2004; Yaniv & Kleinberger, 2000); see also (Mercier & Van der Henst, 2005). For a personal estimate of 0, and a communicated estimate of 100, the average final estimate will be around 30. This bias seems to depend on the distance separating one’s original opinion from the one that is