Vincent Buskens

Embedded trust: Control and learning

This paper discusses two mechanisms through which social embeddedness can affect trust among actors in cooperative relations. Trust can be based on past experiences with a partner or trust can be built on possibilities for sanctioning an untrustworthy trustee through own or third-party sanctions. These two mechanisms are labeled learning and control. The mechanisms are often left implicit or discussed in isolation in earlier research. Learning and control can operate at different levels: at the dyadic level and at the network level. We argue that for understanding trust the two mechanisms should be studied simultaneously, theoretically as well as empirically. We show that this is more easily said than done by addressing some of the theoretical as well as empirical issues. We offer preliminary evidence of the simultaneous working of the learning and control mechanisms at the dyadic level and the network level.

Dynamics of Networks If Everyone Strives for Structural Holes

When entrepreneurs enter structural holes in networks, they can exploit the related benefits. Evidence for these benefits has steadily accumulated. The authors ask whether those who strive for such structural advantages can maintain them if others follow their example. Burt speculates that they cannot, but a formal demonstration of this speculation is lacking. Using a game theoretic model of network formation, the authors characterize the networks that emerge when everyone strives for structural holes. They find that the predominant stable networks distribute benefits evenly, confirming that no one is able to maintain a structural advantage in the long run.

Micro-macro links and microfoundations in sociology

Using Colemans well-known scheme as an anchor, we review key features of explanations of social phenomena that employ micro-macro models. Some antecedents of micro-macro models and of Colemans scheme as well as some paradigmatic examples of micro-macro links are sketched. We then discuss micro-level assumptions in micro-macro explanations and the robustness of macro-level implications to variations in micro-level assumptions. We conclude with an overview of some recent developments in micro-macro modeling and of the contributions to the special issue.

Social Context and network formation: an experimental study

Recently, there has been increasing interest in determining which social network structures emerge as a consequence of the conscious actions of actors. Motivated by the belief that “networks matter” in reaching personal objectives, it is a natural assumption that actors try to optimize their network position. Starting from the notion that an optimal network position depends on the social context, we examine how actors change their networks to reach better positions in various contexts. Distinguishing between three social contexts (a neutral context, a context in which closed triads are costly, and a context in which closed triads are beneficial), theoretical results predict that emerging networks are contingent on the incentives that are present in these contexts. Experiments are used to test whether networks that are theoretically predicted to be stable are also stable experimentally. We find that emerging networks correspond to a large extent with the predicted networks. Consequently, they are contingent on the incentives present in various social contexts. In addition, we find that subjects tend to form specific stable networks with a higher probability than predicted, namely, efficient networks and networks in which everyone is equally well off.

AN EXPERIMENT ON THE EFFECTS OF EMBEDDEDNESS IN TRUST SITUATIONS: BUYING A USED CAR

This article describes a vignette experiment on the effects of temporal embeddedness and network embeddedness in trust situations. The experiment uses a setting in which a buyer wants to buy a used car from a car dealer. We distinguish between effects on trust of the past relation and the effects of the expected future relation between the buyer and the dealer. A buyer can learn about the trustworthiness of the dealer from past transactions of the dealer. Moreover, the buyer can control the dealer if the buyer and the dealer expect more transactions in the future, because the buyer may sanction the dealer if the dealer would act untrustworthy in the present transaction, for example, by refraining from future transactions. Temporal embeddedness facilitates learning and control through the bilateral relation of the buyer and the dealer, while network embeddedness facilitates learning and control through third parties. In the experiment, subjects are asked to compare different settings for buying a used car, while the relation between the buyer and dealer is varied in these settings. We conclude that both learning and control affect trust at the level of the dyad (temporal embeddedness) as well as at the group-level (network embeddedness).

A New Model for Information Diffusion in Heterogeneous Social Networks

This paper discusses a new model for the diffusion of information through heterogeneous social networks. In earlier models, when information was given by one actor to another the transmitter did not retain the information. The new model is an improvement on earlier ones because it allows a transmitter of information to retain that information after telling it to somebody else. Consequently, the new model allows more actors to have information during the information diffusion process. The model provides predictions of diffusion times in a given network at the global, dyadic, and individual levels. This leads to straightforward generalizations of network measures, such as closeness centrality and betweenness centrality, for research problems that focus on the efficiency of information transfer in a network. We analyze in detail how information diffusion times and centrality measures depend on a series of network measures, such as degrees and bridges. One important finding is that predictions about the time actors need to spread information in the network differ considerably between the new and old models, while the predictions about the time needed to receive information hardly differ. Finally, some cautionary remarks are made about using the model in empirical research.

Testosterone administration modulates moral judgments depending on second-to-fourth digit ratio

Moral judgment involves the interplay of emotions and social cognitions. The male sex-hormone testosterone might play a role in moral reasoning as males are more utilitarian than females in their moral decisions, and high salivary testosterone levels also are associated with utilitarian moral decisions. However, there is no direct evidence for a role of testosterone in moral reasoning. Recent testosterone administration studies show effects on cognitive empathy and social cooperation, which depend on right-hands second-to-fourth (2D:4D) digit ratio, a proxy for prenatal sex-hormone (testosterone-versus-estradiol) priming. Here, in a placebo-controlled within-subjects design using 20 young females we show that 2D:4D predicts 44% of the variance in the effects of testosterone administration on moral judgment. Subjects who show an increase in utilitarian judgments following testosterone administration have significantly higher than average 2D:4D (relatively high prenatal estradiol priming), while subjects showing more deontological judgments following testosterone administration have near-significantly lower 2D:4D (relatively high prenatal testosterone priming). We argue that prenatally-organized differences in aromatase, i.e. conversion from testosterone to estradiol in the brain, might underlie these effects. Our findings suggest that early neurodevelopmental effects of sex steroids play a crucial role in the activational effects of hormones on moral reasoning later in life.

Co-evolution of conventions and networks: An experimental study

We study the emergence of conventions in dynamic networks experimentally. Conventions are modeled in terms of coordination games in which actors can choose both their behavior and their interaction partners. We study how macro-level outcomes of the process in terms of Pareto-efficiency and heterogeneity depend on initial conditions. Moreover, we examine the underlying processes at the microlevel. Predictions are derived from a game-theoretic model which is applied to our experimental conditions by means of computer simulation. The results provide mixed support for the macro-level hypotheses, and indicate possible directions to improve the model at the micro level.

Trust in triads : an experimental study

Pairs of trustors play finitely repeated Trust Games with the same trustee in a laboratory experiment. We study trustfulness of the trustor and trustworthiness of the trustee. We distinguish between learning and control effects on behavior. Learning effects are related to the trustors information on past behavior of the trustee. Control effects are related to the trustors opportunities for sanctioning a trustee in future interactions. Hypotheses on learning and control effects are derived from backward-looking learning models and from forward-looking models of strategic behavior. The design of the experiment, with respect to trustfulness, allows for disentangling learning effects from a trustors own experience with the trustee and learning effects through third-party information. Also, the design enables disentangling control effects on trustworthiness and trustfulness through a trustors own sanction opportunities and opportunities for third-party sanctions. We find evidence for learning and control effects. The trustors own experiences, the experiences of the other trustor, as well as the trustors own sanction opportunities affect trustfulness. We find evidence for control effects on trustworthiness, including effects arising from opportunities for third-party sanctions. However, there is no evidence for control effects through opportunities for third-party sanctions on trustfulness. This could indicate limited strategic rationality of trustors.

Consent or Conflict: Coevolution of Coordination and Networks:

Societies are sometimes divided into groups that behave in different ways or have strongly opposing opinions. At other times, everyone seems to behave according to similar principles and opinions. It is likely that individual decisions on behavior or opinions are affected by social networks through influence and selection processes. However, the outcomes are not necessarily optimal for the society as a whole. Two types of problems might arise: (a) polarization of the society into two camps that do not reach consensus, possibly leading to conflict; (b) actors choosing suboptimal behavior, because changing behavior is too risky if done unilaterally. Simulations show that if a society is rather segregated initially, there exists a heightened probability that this situation will worsen. The effect of network density is twofold. First, density has a positive effect on reaching a uniform opinion and, therefore, decreases the likelihood of polarization. Second, density increases the likelihood that actors do not change their behavior, worsening the inefficiency of already suboptimal initial situations.