BOOKS | Critical Mass: How one things leads to another, by Philip Ball (Arrow Books: 2005).
Is it feasible to come up with practical models that can realistically predict the collective behavior of groups of people? This is a question that we frequently ask ourselves here at THNK. According to Philip Ball the answer is: yes. He makes an impressive and convincing attempt to describe a new "physics of society" that is largely based on the application of the laws of physics to the social sciences—thereby disagreeing with many a conventional economic theory.
The aim of Ball's book is to establish a physics of society that will help us to understand how "patterns of behavior emerge—and patterns undoubtedly do emerge—from the statistical melée of many individuals doing their own idiosyncratic thing." To this end, Ball demonstrates how the application of the laws of modern physics to the social sciences can shed light on the laws of human behavior: we can, he says, make predictions about society without negating the individual's free will, thereby implying that abstract physics-style models have in fact been successful at identifying some general laws and tendencies in social phenomena.
The book is impressive in the extensiveness with which it traces the historical development of socio-physics. It offers a wide-ranging survey of prior attempts to explain social behavior that starts with Thomas Hobbes's mechanistic political philosophy and moves on to Adam Smith, Kant, Auguste Comte and John Stuart Mill, and their theories of government and society. From there, it takes yet another broad and impressive journey through a great variety of areas: from social statistics, flocking, traffic simulation, small world networks, to power laws, phase transitions, the minority game, self-organized criticality, iterated prisoner dilemmas, and more.
Ball notes a return to a scientific view of the social sciences in the past two decades: he explains how unorthodox social theorists are now making use of the latest developments surrounding molecular motion and crystal formation to predict the behavior of various human groups e.g. pedestrians, soccer fans, voters. His examination of the application of physical laws to economics and politics encourages the thought that it is in fact possible to—without dehumanizing your subjects by adopting mechanistic assumptions about individual psychology—produce highly reliable predictions for large-group outcomes based on new social physics models without abridging the unpredictable freedom of individual choice.