Should one use words or money to foster trust of the other party if no means of enforcing trustworthiness are available? This paper reports an experiment studying the effectiveness of two types of mechanisms for promoting trust: a costly gift and a costless message as well as their mutual interaction. We nest our findings in the standard version of the investment game. Our data provide evidence...

We study wrappings of smooth (convex) surfaces by a flat piece of paper or foil. Such wrappings differ from standard mathematical origami because they require infinitely many infinitesimally small folds (“crumpling”) in order to transform the flat sheet into a surface of nonzero curvature. Our goal is to find shapes that wrap a given surface, have small area and small perimeter (for efficient m...

We tested the hypothesis that gifts act as markers of interpersonal similarity for both acquaintances and close relationship partners. Participants were led to believe that a new opposite sex acquaintance (Experiment 1) or romantic partner (Experiment 2) had selected either a desirable or undesirable gift for them. In Experiment 1, men viewed themselves as less similar to their new acquaintance...

The importance of online ratings on sales is widely acknowledged. Firms need to find ways of increasing the number of ratings and rating scores, but how they can achieve this effectively is less well established. In this paper we analyze the impact of an unconditional gift on customers’ rating behavior in an online field experiment. Contrary to prevalent advice, our results suggest that providi...

This paper reports an experiment evaluating the effect of gift giving on building trust. We have nested our explorations in the standard version of the investment game. Our gift treatment includes a dictator stage in which the trustee decides whether to give a gift to the trustor before both of them proceed to play the investment game. We observe that in such case the majority of trustees offer...

Many insects have a mating system where males transfer nutrients to females at mating, which are often referred to as ‘nuptial gifts ’. Among butterflies, some of the characteristic features of these species are polyandry (females mate multiple times), and relatively large male ejaculates. When males produce part of the resources used for offspring, the value of body size might then increase fo...

While nuptial food gifts come in various forms in arthropods, their evolutionary origins are unclear. A previous study on insects has shown that such gifts may arise as a sensory trap that exploits a female's underlying motivation to feed. Here I present independent evidence of a sensory trap in spiders. In certain visually oriented spiders, I suggest that males initially exploit the maternal c...