Many risky actions are carried out under the influence of alcohol. However, the effect of alcoholicintoxicationoverthewillingnesstotakerisksiscomplexandstillremainsunclear.Weconductaneconomicfieldexperimentinanatural,drinkingandrisk-takingenvironment to analyze how both actual and self-estimated blood alcohol concentration (BAC) levels influencesubjects'choicesovermonetarylotteries.Ourresultsrevealanegativeimpactof both actual and self-estimated BAC levels on risk-taking. However, for male and young subjects, we find a positive relationship between BAC underestimation (a pattern of estimation error which mainly occurs at high BAC levels) and the willingness to choose riskierlotteries.Ourfindingssuggestthatariskcompensationmechanismisactivatedonly when individuals' own intoxication level is consciously self-perceived to be high. We concludethereforethathumanpropensitytoengageinriskyactivitiesundertheinfluence of alcohol is not due to an enhanced preference for risky choices. In addition to the suggestion in the existing literature that such propensity is due to a weakened ability to perceiverisks,ourresultsindicatethatanimpairedself-perceptionofownintoxicationlevel mayalsobeanimportantfactor.

The study examines the influence of induced negative mood on dictator game giving (DGG) with two recipients. Participants (N = 63) played the role of a dictator in a three-player dictator game. They could choose among two options: an altruistic option, where two receivers receive 10 Euros and the dictator himself receives nothing, or a selfish option, where the dictator himself receives 5 Euros and both receivers receive nothing. For half of the participants, the second option entailed that only one receiver receives nothing and the other receives 10 Euros. After four rounds, participants were randomly assigned to look at 10 pictures with either positive or negative emotional content with the purpose of inducing positive or negative mood. The results show that looking at pictures with negative emotional content increases anxiety and skin conductance and increases DGG in the remaining four rounds of the game. On the other hand, whether the selfish option would imply that one or both recipients receive nothing does not seem to have a strong influence on DGG.PsycINFO Classification code: 2340; 2360.

We examine the influence of optimism about local and foreign people on social cooperation using a public goods game. Firstly, we find that optimism fuels social cooperation, and secondly, that this positive effect holds when optimism is focused either jointly or individually.

We ran an experiment where the subjects initially played a four-round dictator game, after which each subject was shown either a set of positive images or a set of negative images. Finally the subjects played another four-round dictator game. The effect of the sign of images shown is clear on the players' behaviors: positive images have moderate effects on charitable behavior while negative images dramatically increase charity. We could therefore infer from our experimental results that showing negative images of the Haitian and Chilean catastrophes to the international public would have significant positive impacts on international donations to the victims and the rebuilding programs in both countries.

Is altruism the intuitive behavior in a moral dilemma? Or is selfishness the spontaneous behavior? To answer this question, a dictator game was played in which measures of response time and heart rates were taken with treatments that slightly differ only in the cost associated with the choice of a selfish responding. We find that neither altruism nor egoism is an intuitive process for everyone; rather, altruism is intuitive for altruistic subjects while egoism is intuitive for selfish subjects so that when these subjects are confronted with the choice of the opposite, less probable options, they become more reflective by taking longer time to respond. Lastly, during the decision period, a subject that is altruistic has a higher probability of experiencing an increase in the mean heart rate than a subject that is selfish.