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Which choice is the rational one? An investigation of need for cognition in the ultimatum game
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  Brief Report Which choice is the rational one? An investigation of need for cognitionin the ultimatum game Patrick Mussel a, ⇑ , Anja S. Göritz b , Johannes Hewig a a  Julius-Maximilians-University Würzburg, Department of Psychology, Germany b  Albert-Ludwigs-University Freiburg, Department of Psychology, Occupational and Consumer Psychology, Germany a r t i c l e i n f o  Article history: Available online 31 May 2013 Keywords: Ultimatum gameDecision-makingNeed for cognitionRationality a b s t r a c t Recentstudieshaveidentifiedseveralfactors, suchasnegativeaffectorfairnessconcerns, thatcontributeto explaining the seemingly irrational behavior of receivers in the ultimatum game, namely rejectingunfair offers despite the corresponding personal loss. The opposite behavior, accepting offers, has oftenbeen attributed to rational decision-making, as predicted by rational choice theory. Based on thisassumption, we investigated long reaction times as a behavioral variable and need for cognition as anindividual differences variable as indicators of thoughtful and rational decision-making. To our surprise,wefoundbothreactiontimesandneedforcognitiontopredictrejection, ratherthanacceptanceofunfairoffers. Our results challenge the interpretation of acceptance vs. rejection in terms of rational vs. emo-tional accounts.   2013 Elsevier Inc. All rights reserved. 1. Introduction Rational choice theory assumes that people make decisions onrationalgrounds(Neumann&Morgenstern,1944).Giventhatindi-viduals have complete information about the costs and benefits of all possible behavior options, they will strive to maximize theirutility, preferences, values, or monetary outcomes in an economicdecision-making context, such as bargaining. A frequently usedparadigm to investigate bargaining is the ultimatum game, wherea proposer divides a certain amount of money (i.e., the pie) intotwo parts, one for him- or herself, the other for a receiver (Güth,Schmittberger, & Schwarze, 1982). The receiver has the choice toeitheracceptorrejecttheoffer.Iftheofferisaccepted,bothplayersreceive the amount of money as suggested by the proposer. How-ever, if the offer is rejected, neither of them gets anything.Rational choicetheorypredictsthat receiversshouldaccept anyproposal, as even little money is better than no money. However,research shows that individuals deviate from predictions of ra-tional choice theory, as they tend to reject offers that depart fromequalsplit.Recentresearchhasbeguntoidentifysomeoftheaffec-tiveandpersonalityfactorsthatexplainrejectionofunfairoffersinthe ultimatum game. For example, Hewig et al. (2011) found thatunfair offers in the ultimatum and dictator game elicited negativeaffect, which in turn predicted participants’ decision to reject un-fair offers. PillutlaandMurnighan(1996) foundthat feelingsof an-ger mediatedthe rejectionof unfair offers, whichwereparticularlypronounced when individuals inferred that proposers intended tocause them harm. Furthermore, Brandstätter and Güth (2002)found higher rejection rates for individuals with high levels of benevolence and altruism.While these recent efforts have shed light on the factors influ-encing rejection of unfair offers in the ultimatum game, less isknown about the factors driving acceptance of unfair offers. Fromthis perspective it is interesting to note that even for unfair offerswhereproposers allocate only20%of the pie to the receiver, there-fore keeping 80% for themselves, acceptance rates are typicallyaround50%(e.g.,Hewigetal.,2011).Asoutlinedabove,predictionsof decision making in the Ultimatum game have often been basedon rational choice theory, according to which individuals whomake decisions on rational grounds would accept all offers. How-ever, more recently, the role of rationality has been questioned.For example, Civai, Corradi-Dell’Acqua, Gamer, and Rumiati(2010) report similar rejection rates for a modified ultimatumgame that was played on behalf of a third party, compared toone played by themselves. Interestingly, rejection rates in thethird-party condition could not be explained due to negative emo-tional reactions induced by the unfair offers. Based on these con-tradicting views, we take an individual differences approach toinvestigate the role of rationality in the ultimatum game. 1.1. Need for cognition We assessed individual differences in need for cognition (Caci-oppo, Petty, Feinstein, &Jarvis, 1996;Cacioppo, Petty, &Kao, 1984) 0092-6566/$ - see front matter   2013 Elsevier Inc. All rights reserved.http://dx.doi.org/10.1016/j.jrp.2013.05.007 ⇑ Corresponding author. Address: Julius-Maximilians-University Würzburg,Department of Psychology I, Differential Psychology, Personality Psychology, andPsychological Diagnostics, Marcusstr. 9-11, 97070 Würzburg, Germany. Fax: +49931 31 82425. E-mail address:  patrick.mussel@uni-wuerzburg.de (P. Mussel). Journal of Research in Personality 47 (2013) 588–591 Contents lists available at SciVerse ScienceDirect  Journal of Research in Personality journal homepage: www.elsevier.com/locate/jrp  as an indicator of the extent to which individuals make decisionson rational grounds. According to the authors, ‘‘individuals highin need for cognition were proposed to naturally tend to seek, ac-quire, think about, and reflect back on information to make senseof stimuli, relationships, and events in their world. Individualslow in need for cognition, in contrast, were characterized to morelikelyrelyonothers,cognitiveheuristics, orsocialcomparisonpro-cesses’’ (Cacioppo et al., 1996, p. 198). Initially studied in the con-text of social psychology, the construct has in the meantime beenapplied in diverse settings, such as developmental and cognitivepsychology, behavioral medicine, education, journalism, market-ing, and law (Cacioppo et al., 1996). Frequently researched topicswithin the need for cognition literature include type and amountof information being sought out and later recalled, influences of number and quality of persuading arguments, and enjoyment of cognitiveendeavors. For example, individualshighinneedfor cog-nition are more likely to base their beliefs and judgments on ra-tional considerations (Leary, Sheppard, McNeil, Jenkins, & Barnes,1986).Therefore, according to the definition and based on empiricalresults,individualshighinneedforcognitionshouldbemorelikelyto reflect, think about and, therefore, make decisions on rationalgrounds, compared to individuals low in need for cognition.According to rational choice theory, individuals who make theirdecisions on rational grounds accept more offers in the ultimatumgame.Therefore, weexpectthatindividualshighinneedforcogni-tion will accept more offers in the ultimatum game, compared toindividuals low in need for cognition. 1.2. Reaction times In addition to investigating the influence of need for cognitionon acceptance rates, we recorded reaction times for decision-mak-ing. We had no a priori hypothesis regarding the correlation be-tween need for cognition and reaction times. As need forcognition is positively associated with general mental ability (Cac-ioppo et al., 1996), one might expect faster processing and, there-fore, smaller reaction times. Alternatively, given the moredeliberate and thoughtful cognitive style of individuals high inneedforcognition, onemightexpectlargerreactiontimes.Regard-ing the role of rationality in the ultimatum game, we propose thatlargerreactiontimesmightbeanindicatorofmoredeliberatedeci-sion making and, hence, of stronger rationality. Indeed, accordingto dual process theories, rational and conscious decisions are asso-ciatedwithlargerreactiontimes,comparedtoautomatic,emotion-ally driven decisions (Strack & Deutsch, 2004). Therefore, if accepting offers in the ultimatum game is indeed associated withrational decision making, as proposed by rational choice theory,larger reaction times should accompany higher acceptance rates. 2. Method  2.1. Sample A total of 7319 individuals were contacted via WiSo-Panel, aweb-based respondent pool with people from all walks of life thatoffers monetary and nonmonetary compensation in return for sur-vey participation (Göritz, 2009). Individuals were briefly informedaboutthepurposeandcontentofthestudy.Atotalof1326individ-uals agreed to participate and, subsequently, were directed to anonlineadministeredexperimenttakingapproximately20min.Par-ticipants were, on average, 39years old ( SD  =12.9); 61% were fe-male. The sample comprises a wide range of educational levels,with 9% reporting 9years of school as highest educational degree,26% reporting 10years of school (comparable to O-level), 34% auniversity-entry degree (comparable to A-level), 27% a universitydegree and 2% a doctoral degree.  2.2. Task and procedure Each participant played the ultimatum game repeatedly in aseriesof42one-shottrialsasareceiver.Participantsweretoldthatthey would receive offers by participants who had played the ulti-matum game previously. If they decided to accept the offer, theyboth would get paid real money according to the offer. However,iftheydecidednottoaccept,bothwouldreceivenothing.Eachtrialbegan with a picture of the proposer (see Fig. 1). Pictures were ta-ken from participants who had played the ultimatum game previ-ously as well as from an archive of face images. After a fixationcross (500ms), the offer (a share of 12Cent) was displayed, graph-ically illustrated in a pie chart. Offers differed in fairness on sevenlevels, which ranged from 7Cent (overly fair) to 1Cent (very un-fair), with 6Cent being a fair offer (i.e., half of the money to theproposer and half of the money to the receiver). Each of the sevenoffers was presented six times. As a one-shot procedure, differentpictures of proposers were used for each offer, counter-balancedfor gender and facial expression of the proposer (results for theseexperimental manipulations are reported elsewhere). The orderof the 42 offers was randomized separately for each participant.Participants decided whether to accept or reject an offer whilethe offer was displayed. The maximum time for the reaction wasgenerously set to 3s; however, reaction times were much faster( M   =763ms;  SD  =390ms). After the decision, feedback was givenregarding the amount of money earned by the receiver. Partici-pants were paid according to their decisions in the ultimatumgame, that is, they actually received the money from accepted of-fers, with a maximum of   €  1.68 if all offers were accepted.  2.3. Measures For theassessment of needfor cognition, the18-itemshort ver-sion developed by Cacioppo et al. (1984); (German translationadapted from Bless, Wänke, Bohner, Fellhauer, & Schwarz, 1994)was used. In the present study, the scale had an internal consis-tency of   a  =.87 ( M   =84.1;  SD  =15.2).  2.4. Statistical analyses We used logit mixed models to analyze the influence of offersize (7 levels: 1–7Cent), need for cognition and reaction time ondecision making. Need for cognition and reaction times were z-standardized prior to the analysis. Additionally, we modeled fixedinteraction effects between offer size and need for cognition aswell as offer size andreactiontime. Missingvalues occurredif par-ticipantsdidnotrespondwithinthe3-stimeframe.Missingvaluesoccurredinlessthan1%ofdecisionsandweresubstitutedbymod-al value computed across the responses of the same participantand the same offer. Critical alpha level was set at .05. 3. Results Acceptance rate across all offers was 71%. In line with priorstudies (e.g., Sanfey et al., 2003), a strong effect of offer size onthe acceptance rate was found:  F  (6,56)=212.5;  p  <.01. Inspectionof descriptive statistics revealed that fair offers (6Cent) and overlyfair offers (7Cent) were generally accepted, whereas acceptancerates decreased as offers became more and more unfair. Specifi-cally, acceptance rates were 92% for offers of 7Cent, 93% for offersof 6Cent, 84% for offers of 5Cent, 72% for offers of 4Cent, 59% foroffers of 3Cent, 50% for offers of 2Cent, and 44% for offers of 1Cent. P. Mussel et al./Journal of Research in Personality 47 (2013) 588–591  589  We found a significant main effect of need for cognition on theacceptance rate ( F  (1, 53)=5.0;  p  =.02). However, to our surprise,we found that the direction of the effect was opposite to ourhypothesis (ln(OR)=  0.097); that is, individuals high in need forcognition rejected more offers, compared to individuals low inneed for cognition. Additionally, a significant interaction betweenneed for cognition and offer,  F  (7, 53)=3.3;  p  <.01, indicated thatthe effect was moderated by offer size. Inspection of coefficientsindicatedasignificantpositiverelationbetweenneedforcognitionand acceptance rate for overly fair offers of 7Cent, whereas a neg-ative relation was observed for unfair offers of 1Cent, 2Cents, and3Cents.Nodifferencewasobservedforoffersof4Cent,5Cent,and6Cent. Coefficients are displayed in Fig. 2. To illustrate the patternof results, Fig. 2 also depicts acceptance rates for individuals scor-ing at least one standard deviation above ( N   =201) or below( N   =201) the mean in need for cognition.Reaction times were uncorrelated with need for cognition( r   =.02;  p  =.62). Regarding our hypotheses, the pattern of resultsfound with need for cognition on acceptance rates was mirroredbythat withreactiontime. Again, longer reactiontimes were asso-ciated with higher rates of rejection:  F  (1, 55)=557.1;  p  <.01;ln(OR)=  0.51. Additionally, a significant interaction betweenreactiontime and offer was observed:  F  (7,55)=96.4;  p  <.01. Coef-ficients indicated that the effect was strongest for unfair offers of 3Cent (ln(OR)=  0.63), 2Cent (  0.77), and 1Cent (  0.87). Coeffi-cientsfor4Cent(  0.37),5Cent(  0.15),6Cent(  0.38),and7Cent(  0.28)werealsosignificant(all  p  <.01)andinthesamedirection,although smaller in magnitude. 1 4. Discussion Inthe present study, we usedan individual difference approachto investigate decision making in the ultimatum game. We foundthatoverlyfairofferswereacceptedmoreoftenbyindividualshighin need for cognition. However, across all offers, and particularlyfor unfair offers, the opposite was true: We found that more ra-tional and thoughtful decisions as indicated by higher scores onneed for cognition as well as longer reaction times resulted in en-hanced rejection rates.Regarding overly fair offers, decreased rejection rates for indi-viduals high, compared to low, in need for cognition are expected.As there is obviously no reason to reject an overly fair offer, theseresults underscore that need for cognition is associated with amore thoughtful and, in this case, reasonable decision. Rejectionof overly fair offers might, therefore, reflect other processes thanrationality. For example, overly fair offers deviate from equal splitand might, therefore, be driven by inequity aversion; additionally,participants might mistrust on account of the unusual occurrencethat somebody offers more than half of the pie.Regarding unfair offers, results from the present study suggestthat accepting unfair offers in the ultimatum game might not beas rational as is often suggested. Thereby, it is important to notethat the study at hand did not aimat falsifyingrational choice the-ory. Rational choice as a descriptive theory (i.e., all individualsshould accept all offers, irrespective of their level on need for cog-nition)hasbeenfalsifiedalongtimeago(Güthetal.,1982);rather,the present results challenge how results from studies using theultimatumgame shouldbe interpreted. Recent investigations havesometimes assumed that accepting unfair offers is driven by ra-tional decision-making, whereas rejecting unfair offers has beeninterpreted as emotional or irrational. For example, Sanfey et al.(2003) interpreted that ‘‘unfair offers in the ultimatum game in-duce conflict in the receiver between cognitive (‘‘accept’’) andemotional (‘‘reject’’) motives’’ (p. 1756); Osumi and Ohira (2009)refer to the conflict ‘‘between motivations of rational acceptanceand irrational rejection‘‘ (p. 78); and Boksem and De Cremer(2010) refer to the ‘‘seemingly irrational decision-making process’’(p. 119). Our results are in line with recent studies that have crit-ically questioned the interpretation of acceptance as a rational act(e.g., Civai, Corradi-Dell’Acqua, Gamer, & Rumiati, 2010; Xiang,Lohrenz, & Montague, 2013). Specifically, we found that need forcognition as a personality indicator and reaction times as a behav-ioral indicator of more rational and deliberate decision makinglead to increased rejection of unfair offers. 2 Fig. 2.  Acceptance rates in the ultimatum game for seven shares of a total of 12Cent, separately for individuals low (below 1 SD) and high (above 1 SD) in needfor cognition (NFC). Coefficients from mixed logit analysis (i.e., ln(OR)) aredisplayed for each offer; positive values indicate that individuals high, comparedto low, in need for cognition accepted more offers.  *  p  <.05. Fig. 1.  Task timeline for the ultimatum game. 1 As suggested by an anonymous reviewer, we performed an additional ANOVAwith reaction time as independent variable and offer size as independent variable. Wefound a significant main effect for offer size:  F  (6,1023) = 118.2;  p  < .01; g 2 = .09. Posthoc tests revealed that responses to fair offers (6 Cent, 687ms) were fastest, followedby offers of 7 Cent (715ms), 5 Cent (761ms), and 4 Cent (788ms; all pairwisecomparisons significant on  p  < .01); responses to unfair offers of 3 Cent (799ms), 2Cent (801ms), and 1 Cent (802ms, pairwise comparisons not significant) wereslowest. 2 As pointed out by an anonymous reviewer, some recent studies found decreasedrejection times after a time delay between the offer and the response (Grimm &Mengel, 2011; Neo, Yu, Weber, & Gonzalez, 2013). However, the time delay in thesestudies was between 10 and 15 min, compared to a fraction of a second in the presentstudy. Therefore, the processes which might account for this effect, such as weakeremotional responses after the time delay, are unlikely to occur in the presentexperimental setting. 590  P. Mussel et al./Journal of Research in Personality 47 (2013) 588–591  Interestingly, our resultsareinlinewithastudyusingtranscra-nialmagneticstimulation(Knochetal.,2006),reportingdisruptionof the right dorsolateral prefrontal cortex to result in higher ratesof accepted unfair offers. As this brain region is widely thoughttobeinvolvedinexecutivecontrol, goal maintenanceandtheinhi-bition of responses, the authors interpreted their result as indicat-ing that impulses associated with self-interest and, therefore,acceptance of offers, need to be controlled to maintain culture-dependent fairness. Interestingly, these brain areas have also beenassociated with the personality trait intellect (DeYoung, Shamosh,Green, Braver, & Gray, 2009), a construct highly correlated withneed for cognition (Mussel, 2010). Transferring their findings tothe present study, it can be speculated that the rejection of unfairoffers is a rational and deliberate process. Therefore, future re-search might, for example, investigate whether rejection of unfairoffers requires executive control to resist more spontaneous im-pulses of accepting offers.It is also instructive to distinguish between short-term andmedium- to long term utility as well as between personal andgroup-related utility. A rational decision-maker who aims at max-imizing short-term, personal utility would accept all offers to re-ceive a higher monetary output. However, an equally rationaldecision-maker who pursues different goals, especially maximiz-ing medium- to long-term utility for a whole group would indeedreject unfair offers to penalize proposers for violating culturalnorms of fairness and equity. According to our results, need forcognition would reflect this latter aspect. Evolutionary theorieshave interpreted such decisions as altruistic punishment becauseof the personal costs accompanying the punishment (Fehr & Gäch-ter, 2002). More generally speaking, a differentiation between ra-tional and emotional decision-making might be too simplistic.Rather, rationality and emotion should not be considered as con-tradicting but as complementing each other, whereat emotions as-sist sound, rational decision making (Bechara & Damasio, 2005).That being said, the search for determinants explaining why, inmanycases, unfair offers are actuallyaccepted, is still pending. Weshowed that rational, deliberate thinking is not such a determi-nant. A potential variable for future research might be the investi-gation of underlying values related to striving to maximize utilityand monetary outcome, such as selfishness or economic values(Rokeach, 1973) or the propensity to engage in self-interest seek-ing (Meyer, 1992). References Bechara, A., & Damasio, A. R. (2005). 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