Results on Range Image Segmentation for Service Robots

This paper presents an experimental evaluation of a plane extraction method using various line extraction algorithms. Four different algorithms are chosen, which are well known in mobile robotics and computer vision. Experiments are performed on two sets of 25 range images either obtained by simulation or acquired by a proprietary 3D laser scanner. The performance of the range image segmentation is measured in terms of an average segment classification ratio. Moreover, the speed of the method is measured to conclude on the suitability for service robot applications

Effort Perception is Made More Accurate with More Effort and When Cooperating with Slackers

Recent research on the conditions that facilitate cooperation is limited by a factor that has yet to be established: the accuracy of effort perception. Accuracy matters because the fitness of cooperative strategies depends not just on being able to perceive others' effort but to perceive their true effort. In an experiment using a novel effort-tracker methodology, we calculate the accuracy of human effort perceptions and show that accuracy is boosted by more absolute effort (regardless of relative effort) and when cooperating with a "slacker" rather than an "altruist". A formal model shows how such an effort-prober strategy is likely to be an adaptive solution because it gives would-be collaborators information on when to abort ventures that are not in their interest and opt for ones that are. This serves as a precautionary measure against systematic exploitation by extortionist strategies and a descent into uncooperativeness. As such, it is likely that humans have a bias to minimize mistakes in effort perception that would commit them to a disadvantageous effort-reward relationship. Overall we find support for the idea that humans have evolved smart effort detection systems that are made more accurate by those contexts most relevant for cooperative tasks

Trust and Reciprocity: Are Effort and Money Equivalent?

Trust and reciprocity facilitate cooperation and are relevant to virtually all human interactions. They are typically studied using trust games: one subject gives (entrusts) money to another subject, which may return some of the proceeds (reciprocate). Currently, however, it is unclear whether trust and reciprocity in monetary transactions are similar in other settings, such as physical effort. Trust and reciprocity of physical effort are important as many everyday decisions imply an exchange of physical effort, and such exchange is central to labor relations. Here we studied a trust game based on physical effort and compared the results with those of a computationally equivalent monetary trust game. We found no significant difference between effort and money conditions in both the amount trusted and the quantity reciprocated. Moreover, there is a high positive correlation in subjects' behavior across conditions. This suggests that trust and reciprocity may be character traits: subjects that are trustful/trustworthy in monetary settings behave similarly during exchanges of physical effort. Our results validate the use of trust games to study exchanges in physical effort and to characterize inter-subject differences in trust and reciprocity, and also suggest a new behavioral paradigm to study these differences

Correlates of Cooperation in a One-Shot High-Stakes Televised Prisoners' Dilemma

Explaining cooperation between non-relatives is a puzzle for both evolutionary biology and the social sciences. In humans, cooperation is often studied in a laboratory setting using economic games such as the prisoners' dilemma. However, such experiments are sometimes criticized for being played for low stakes and by misrepresentative student samples. Golden balls is a televised game show that uses the prisoners' dilemma, with a diverse range of participants, often playing for very large stakes. We use this non-experimental dataset to investigate the factors that influence cooperation when “playing” for considerably larger stakes than found in economic experiments. The game show has earlier stages that allow for an analysis of lying and voting decisions. We found that contestants were sensitive to the stakes involved, cooperating less when the stakes were larger in both absolute and relative terms. We also found that older contestants were more likely to cooperate, that liars received less cooperative behavior, but only if they told a certain type of lie, and that physical contact was associated with reduced cooperation, whereas laughter and promises were reliable signals or cues of cooperation, but were not necessarily detected

Choosy Moral Punishers

The punishment of social misconduct is a powerful mechanism for stabilizing high levels of cooperation among unrelated individuals. It is regularly assumed that humans have a universal disposition to punish social norm violators, which is sometimes labelled “universal structure of human morality” or “pure aversion to social betrayal”. Here we present evidence that, contrary to this hypothesis, the propensity to punish a moral norm violator varies among participants with different career trajectories. In anonymous real-life conditions, future teachers punished a talented but immoral young violinist: they voted against her in an important music competition when they had been informed of her previous blatant misconduct toward fellow violin students. In contrast, future police officers and high school students did not punish. This variation among socio-professional categories indicates that the punishment of norm violators is not entirely explained by an aversion to social betrayal. We suggest that context specificity plays an important role in normative behaviour; people seem inclined to enforce social norms only in situations that are familiar, relevant for their social category, and possibly strategically advantageous

Public Goods, Signaling, and Norms of Conscientious Leadership

I study a sequential-move public goods game based on the notion that leadership comes with an obligation; conscientious leadership. Provision by the leader of an amount of the public good below a minimum imposes a psychological cost on the follower which increases his unit cost of contribution. The leader has private information about his type and his cost of contributing to the public good. The model combines a follower’s concern for fairness and informational signaling about conscientious leadership. I find that, under certain conditions, the follower’s equilibrium contribution is an increasing or non-monotonic function of the leader’s equilibrium contribution. The non-monotonicity result is consistent with evidence in a recent field experiment (Jack and Recalde, J. Public Econ, 2015) but cannot be obtained in previous theoretical models of voluntary public goods games that were based on only signaling information (i.e., about the quality of the public good or the return to contributions to the public good). Surprisingly, I find that, for this result to hold, the follower’s distaste for non-conscientious leadership must be sufficiently low. I also find that the leader may not act conscientiously if he does not have an informational advantage to exploit

Measuring Trust: Experiments and Surveys in Contrast and Combination

Trust is a concept that has attracted significant attention in economic theory and research within the last two decades: it has been applied in a number of contexts and has been investigated both as an explanatory and as a dependent variable. In this paper, we explore the questions of what exactly is measured by the diverse survey-derived scales and experiments claiming to measure trust, and how these different measures are related. Using nationally representative data, we test a commonly used experimental measure of trust for robustness to a number of interferences, finding it to be mostly unsusceptible to stake size, the extent of strategy space, the use of the strategy method, and the characteristics of the experimenters. Inspired by criticism of the widespread trust question used in many surveys, we created a new, improved survey trust scale consisting of three short statements. We show that the dimension of this scale is distinct from trust in institutions and trust in known others. Our new scale is a valid and reliable measure of trust in strangers. The scale is valid in the sense that it correlates with trusting behaviour in the experiment. Both survey and experimental measure correlate with related factors such as risk aversion, being an entrepreneur or a shareholder. Furthermore, we demonstrate that the survey measure's test-retest reliability (six weeks) is high. The experimental measure of trust is, on the other hand, not significantly correlated with trust in institutions nor with trust in known others. We conclude that the experimental measure of trust refers not to trust in a general sense, but specifically to trust in strangers