For those looking for a more academic take on signaling (particularly from a sociological point of view), Gambetta's Codes of the Underworld is a great find. Gambetta uses the extreme case of cooperation amongst criminals to tease out more general dynamics of trust, signaling, and communication. The Mafia can be considered a "hard-case" for theories of signaling trust; given the extreme incentives for criminals to lie and the lack of credibility they wield given the very fact that they are criminals, how is it that criminals manage to coordinate their actions and trust each other at all? By understanding how trust works in this harsh environment we learn something about how to signal trustworthiness in broader, less restrictive environments. As Gambetta notes, "Studying criminal communication problems, precisely because they are the magnified extreme versions of problems that we normally solve by means of institutions, can teach us something about how we might communicate, or even should communicate, when we find ourselves in difficult situations, when, say, we desperately want to be believed or keep our messages secret." The book is a great example of studying deviant cases or outliers, particularly when the area of study is not well worn. This is a valuable general methodological lesson. We are typically taught to avoid outliers as they skew analysis. However, they can be of great value in at least two circumstances: 1) Generating hypotheses in areas that have not been well studied and 2) Testing hypotheses in small-N research designs, where hard cases can establish potential effect and generalizability and easy cases suggest minimal plausibility.
Gambetta takes a number of criminal actions and views them through the lens of signaling. This allows readers to see actions, in many cases, in completely new ways, highlighting the instrumental causes of behavior. For example, Gambetta looks at how criminals solve the problem of identifying other criminals by selectively frequenting environments where non-criminals are not likely to go. Since criminals cannot advertise their criminality, they face a coordination problem. Frequenting these locations acts as a screening mechanism since only those that are criminals are likely willing to pay the costs to frequent these locations. (This ignores the issue of undercover law enforcement, but Gambetta deals with that as well). Gambetta also makes the reader look at prison in a new light. Criminals derive a number of advantages from serving time in prison, not the least of which is providing them with a signaling mechanism for communicating their credibility to other criminals (as prison time can be verified by third parties). Additionally, many criminal organizations will require that new members have already served time before they are allowed to join. Moreover, Gambetta explores how incompetence can work to a criminal's advantage, since it can signal loyalty to a boss who provides the criminals only real means of income.
Gambetta also looks at the conspicuous use of violence within prisons. This isn't a new topic, as any law enforcement drama will undoubtedly portray the dilemma of a new inmate who must establish their reputation for toughness and resolve or else suffer constant assaults by other inmates. However, Gambetta makes it interesting by embedding the act in a signaling framework. First, Gambetta's hypothesis regarding the importance of non-material interests is borne out by various studies. Among others, he cites one study of prison conflict that found that "[n]on-material interests (self-respect, honour, fairness, loyalty, personal safety and privacy) were important in every incident." While only some violent conflicts occur for the immediate purpose of getting or keeping resources, all of them have to do with establishing one's reputation or correcting wrong beliefs about it. Even "a conflict that began over the disputed ownership of some item could quickly be interpreted by both parties as a test of who could exploit whom." Second, Gambetta hypothesizes that we should expect to see more fights when prisoners do not have enough of a violence track record when they first arrive in prison. One observable implication of this is higher rates of prison violence among female prisoners and younger prisoners. In fact, the empirical record bears this out quite nicely. Rates of violence are inversely related to age, providing " a plausible social rather than biological explanation" for youth violence. Additionally, Gambetta finds that, although less violent in the outside world, "women become at least as violent and often more prone to violence than men". Interesting, women are less often convicted of violent offenses, suggesting that the results are not simply the result of selection effects.
Overall, Gambetta's book is a unique and thought-provoking work. For those with a strong interest in communication and signaling, it is a must read.
