Michael Näf

Learn More
Influential neurocomputational models emphasize dopamine (DA) as an electrophysiological and neurochemical correlate of reinforcement learning. However, evidence of a specific causal role of DA receptors in learning has been less forthcoming, especially in humans. Here we combine, in a between-subjects design, administration of a high dose of the selective(More)
Event scheduling is a group decision-making process in which social dynamics influence people's choices and the overall outcome. As a result, scheduling is not simply a matter of finding a mutually agreeable time, but a process that is shaped by social norms and values, which can highly vary between countries. To investigate the influence of national(More)
Goals are an important motivator. But little is known about why and how people set them. We address these questions in a model based on two stylized facts. i) Goals serve as reference points for performance. ii) Present-biased preferences create self-control problems. We show the power and limits of self-regulation through goals. Goals increase an(More)
Behavioral endocrinological research in humans as well as in animals suggests that testosterone plays a key role in social interactions. Studies in rodents have shown a direct link between testosterone and aggressive behavior(1) and folk wisdom adapts these findings to humans, suggesting that testosterone induces antisocial, egoistic or even aggressive(More)
This paper provides the first experimental test of Edward Lazear’s (1979) model of deferred compensation. We examine the relationship between firms’ wage offers and workers’ effort supply in a multi-period environment. If firms can ex ante commit to a wage schedule with deferred compensation, workers should respond by supplying sufficient effort to avoid(More)
A contribution to a special issue on Hormones and Human Competition. Studies in non-human animals and humans have demonstrated the important role of testosterone in competitive interactions. Here, we investigated whether endogenous testosterone levels predict the decision to compete, in a design excluding spite as a motive underlying competitiveness. In a(More)
Since 2000, a surprisingly high number of macroscopical gonad alterations has been reported in whitefish (Coregonus spp.) from Lake Thun, Switzerland. This unique phenomenon is still unexplained and has received much public attention. As one possible trigger for these effects, the presence of persistent, bioaccumulative and toxic compounds acting as(More)