Some weeks ago I was approached by an editor from Cambridge Scholars Publishing (an imprint I’ve never heard about before) with a request to review a book that presented a new theory of history. I agreed, the book arrived in the due course, and so here are my thoughts as promised.
First, about the author. Jim Penman received his Ph.D. in history in 1985, but he didn’t become an academic, instead going into business. He started a servicing franchise, called Jim’s Group, which eventually become very successful. According to a recent interview, a career in business wasn’t his first choice; he went into it because he couldn’t get a job in academia.
Jim Penman at the Jim’s Group headquarters in 2012. Photo: Luis Enrique Ascui. Source
But he kept his interest in history through the years, and now he is out with the book, Biohistory, which summarizes his thinking and theories about such Big Questions as, why are some societies are much wealthier than others? Why do civilizations fall? These are, of course, questions that have been asked many thinkers in the past, and ones that we are addressing, or plan to address, in our own work within the Seshat project.
The book itself is clearly written and well-researched. Penman is up on current literature and cites most important recent research in theoretical social history, including my own (on which more below).
So what is Biohistory? Basically, it’s the idea that the main moving force of history is the biological characteristics of individual people. Penman comes up with several such characteristics, assigning them letters C, V, S, and so on. For example, C is “a physiological system that adjusts behavior to conditions of limited food. … Characteristics of C in humans include hard work, discipline, and willingness to sacrifice present consumption for future benefit.” Penman then comes up with a variety of factors that affect how C changes with time in a particular society.
The book is quite long (over 600 pages) and presents many different ideas, all of which I lack space to discuss. So let’s take one of the more dynamical theories in the book, which Penman calls “lemming cycles.” I chose to address this particular theory, because I have some expertise in lemming cycles (in fact, my greatest scientific coup was publishing a paper in Nature that was featured on the journal issue’s cover about lemming cycles).
Perhaps more relevant is that I have also done a lot of work on the structural-demographic dynamics, which is an alternative theory to what Penman proposes.
Here’s a summary of Penman’s theory (from the Glossary at the end of the book):
A fluctuation in a trait known as ‘G’, believed to be a mammalian mechanism triggered by occasional food shortages which causes an alternation between V and C. Reflected by changes in population growth, political cohesion, and habits of thought. Normally around 300 years in humans but lengthens in ‘Dark Ages’ following the collapse of civilizations.
There are two major problems with this theory. The first one is that it is of the kind that I call ‘the exogenous driver’ mechanism. As far as I could determine (there are no explicit mathematical equations), at various phases of G—G+30 years, G+60 years, etc.—various events are supposed to happen. It’s like a clock, in which the hour hand sweeps around the clock face and triggers various events (e.g., an alarm that wakes you up). This is not a truly mechanistic, dynamical theory, because it doesn’t explain why different events are triggered at various parts of the cycle.
In contrast, the structural-demographic theory uses the systems approach. It represents different parts of the social system—general population, elites, the state—as mutually interactive compartments. The secular cycles arise as a result of nonlinear feedback loops relating these compartments to each other. It’s a very different kind of theory. It is also formulated as a suite of explicit mathematical models. The theory generates quantitative predictions that can be, and have been tested with dynamical data (see our book with Sergey Nefedov, Secular Cycles).
The feedback loops in the Structural Demographic Theory
In Chapter 8, devoted to the ‘lemming cycles,’ Penman doesn’t cite our work, although he goes much over the same data for England and France. Our book Secular Cycles is cited in a long footnote on p.382. There Penman acknowledges our rigorous mathematical model and empirical time-series, but he criticizes us as follows.
However, there are a number of basic flaws with their model, starting with the obvious fact that Malthusian propositions do not hold in the state of industrial innovation. Their model oversimplifies the nature of human motivation, dealing only with the reality of sexual reproduction beyond the carrying capacity of the land. Biohistory provides a far richer understanding of human motivations based on actual experimental case studies.
This critique misrepresents our theory. Although we are happy to acknowledge our intellectual debt to Thomas Robert Malthus and David Ricardo, it is by no means a neo-Malthusian theory, because it pays much more attention to the social structure—the relations between the elites, the general population, and the states—than to demographics. And it translates surprisingly well to the industrializing and industrial societies (see my article, it’s also will be dealt in a forthcoming book).
‘Biohistory’, on the other hand, with its focus on individuals and their biological characteristics, completely misses out on the all-important social dynamics. Penman never addresses the biggest puzzle of human social evolution—how humans evolved the capacity to cooperate in huge groups of genetically unrelated individuals. And why do some societies cooperate much better than others? That is the key to understanding why some countries are wealthy and peaceful, and others are poor and convulsed by internal warfare.
I am sympathetic to the valiant efforts of those, like Jim Penman, who have the courage to propose radically new theories. But the science of human history has moved beyond the valiant attempts of brilliant individuals to propose new explanations. We are now in the less glamorous and more laborious phase, when new theories need to be translated into mathematical models, which can generate quantitative predictions that are subsequently tested with rich databases.