Low-level “adaptive” and higher-level “sophisticated” human reasoning processes have been proposed to play opposing roles in the emergence of unpredictable collective behaviors such as crowd panics, traffic jams, and market bubbles. While adaptive processes are widely recognized drivers of emergent social complexity, complementary theories of sophistication predict that incentives, education, and other inducements to rationality will suppress it. We show in a series of multiplayer laboratory experiments that, rather than suppressing complex social dynamics, sophisticated reasoning processes can drive them. Our experiments elicit an endogenous collective behavior and show that it is driven by the human ability to recursively anticipate the reasoning of others. We identify this behavior, “sophisticated flocking”, across three games, the Beauty Contest and the “Mod Game” and “Runway Game”. In supporting our argument, we also present evidence for mental models and social norms constraining how players express their higher-level reasoning abilities. By implicating sophisticated recursive reasoning in the kind of complex dynamic that it has been predicted to suppress, we support interdisciplinary perspectives that emergent complexity is typical of even the most intelligent populations and carefully designed social systems.

Cognitive mechanisms for human flocking dynamics
Seth Frey, Robert L. Goldstone

Journal of Computational Social Science
September 2018, Volume 1, Issue 2, pp 349–375

Source: link.springer.com

Zipf’s law states that the frequency of an observation with a given value is inversely proportional to the square of that value; Taylor’s law, instead, describes the scaling between fluctuations in the size of a population and its mean. Empirical evidence of the validity of these laws has been found in many and diverse domains. Despite the numerous models proposed to explain the presence of Zipf’s law, there is no consensus on how it originates from a microscopic process of individual dynamics without fine-tuning. Here we show that Zipf’s law and Taylor’s law can emerge from a general class of stochastic processes at the individual level, which incorporate one of two features: environmental variability, i.e., fluctuations of parameters, or correlations, i.e., dependence between individuals. Under these assumptions, we show numerically and with theoretical arguments that the conditional variance of the population increments scales as the square of the population, and that the corresponding stationary distribution of the processes follows Zipf’s law.

Zipf’s and Taylor’s laws

Charlotte James, Sandro Azaele, Amos Maritan, and Filippo Simini
Phys. Rev. E 98, 032408 – Published 12 September 2018

Source: journals.aps.org