Scale: The Universal Laws of Growth, Innovation, Sustainability, and the Pace of Life, in Organisms, Cities, Economies, and Companies

by Geoffrey West

This is reminiscent of the ubiquitous generality of the “bell-curve” distribution used for describing statistical variations around some average value. Technically this is called a Gaussian or normal distribution and arises mathematically whenever a sequence of events or entities, whatever they are, are randomly distributed, uncorrelated, and independent of one another. So, for example, the average height of men in the United States is about five feet ten inches (1.77 meters) and the frequency distribution of their heights around this mean value—that is, how many men there are of a given height—closely follows a classic Gaussian bell-curve distribution. This tells us what the likelihood is of someone being a specific height. Gaussian statistics are used across all of science, technology, economics, and finance to assign statistical probabilities of various events happening such as in weather forecasting or for drawing conclusions from polling surveys.