A1 Generalized collapse of trust

Topic

Trust, cooperation, and collective action constitute the sixth and final track of Psychophysics; this track describes how trust forms and erodes within a population, as well as the collective action and free-rider problems that arise when such trust is absent. The collapse of generalized trust is the first anomaly in this track, describing a spiral of mutual distrust—a generalized version of the "tragedy of the commons" where cooperation ceases to be the rational choice for the individual, not because no one *wants* to cooperate, but because no one expects others to do so anymore.

The variable triggering this anomaly is the observed rate of non-compliance or betrayal crossing the threshold that makes ceasing cooperation rational: as long as that rate remains low, cooperation continues to be the rational response for each individual, because the expectation that others will also cooperate is supported by evidence; once the observed non-compliance rate crosses that threshold, ceasing cooperation becomes the rational choice even for someone who would prefer to cooperate, because doing so in an environment where others no longer cooperate leaves one vulnerable. The spiral is self-reinforcing: each new instance of non-compliance raises the observed rate, making it rational for more individuals to stop cooperating, which in turn drives the non-compliance rate even higher.

This track is closely related to—though distinct from—the "pluralistic ignorance" described in the context of social diffusion and contagion. That anomaly describes a population concealing its private opinions for fear of social sanction, thereby maintaining an appearance of legitimacy that masks actual disagreement; this track, by contrast, describes a population that stops cooperating as a rational response to observed evidence of non-compliance by others, without any need for concealment. Both can coexist within the same population and reinforce one another: a legitimacy artificially sustained by pluralistic silence is often the very same one that collapses abruptly when the observed rate of non-compliance crosses the threshold at which ceasing to cooperate becomes rational—because both forms of erosion leave the population without any mechanism, whether for expression or cooperation, to sustain the system.

ID:4724