Hamilton's Unequation and the Principle of Division of Labour in Complex Societies

A naturalistic theory for Adam Smith's principle of division of labour

The evolution of "strong" altruism is possible according to Hamilton's unequation c/b < r. 

Yet, in research seldom it has been asked for the consequences of the division of labour (according to Adam Smith) for the evolution of altruism in complex systems and societies. Division of labour diminishes the costs of an altruistic act (c) and enhances the benefit (b) of it by professional specialization. So the mean kinship coefficient r between the altruistic specialist and the receiver of his altruistic acts should be able to be lower than without division of labour for evolutionary stability of this form of altruism.

The "jack of all trades" is not able to act for so many people so easily in altruistic acts than the professional specialist in a well-organized complex society. A pediatrician needs to save the life of 20 children with a mean r of 0,05 to him to do the same - in evolutionary terms - as to rear one own child.

In the theoretical thinking about the evolution of altruism in complex societies at the moment group selection is favored by a lot of scientists (the theory of "superorganism") (W.O.H. Hughes, Samuel Bowles in "Science", E.O. Wilson, D.S. Wilson and B. Hölldobler in "PNAS" and elsewhere). We have hints, that this form of cooperation has to be maintained by "increased rates of dominance, policing, or punishment" (1). But is it possible, that the effects of division of labour are playing a decisive role in the evolution of altruism, cooperation and commitment mainly in complex societies and complex systems (multicellular life) by avoiding such mechanisms of dominance, policing or punishment?

Most societies in human history are confronted with social, not with physical constraints for the growth of their population. If this constraints were diminished by division of labour, by acts of altruism done by professional specialists, than these societies and their inner cooperation could be stabilized by the motivation of kinship altruism even in the greater societies that show diminished mean kinship coefficient between its members.

Hamilton's famous unequation and Adam Smith's principle of division of labour

Hamilton's unequation in words: The (fitness-)costs of an altruistic act divided by the (fitness-)benefit of an altruistic act have to be smaller than the degree of relationship between the altruist and the receiver of the altruist's act. This is the condition of the evolutionary stability of altruistic behaviour. The certain values of costs and benefits are modulated by a lot of circumstances, which have to been taken into account. Since Adam Smith for example it is common sense, that division of labour and specialisation can increase the benefits and diminsh the costs of an altruistic act. By that the degree of relationship between actor and recipient can be reduced, to be evolutionary stable. This way of thinking hasn't been very much explored yet. But this formular can be applied not only to complex human societies, but even to complex, mulitcellular organisms up to organisms, which live in groups and states of every kind.

At first instance this way of thinking could be applied to the first, simple, sedentary tribes, farming communities which have more than 500 members or so. In societies with less than 500 members one has to suppose that simple kinship altruism dominates (for more details, see: 2). But if societies grow, the importance of division of labour for the structuring of societies and social exchange inside of them grow, while the degree of relationship between the members of a given society declines. No one knows at the moment which of both grows or declines faster in relationship to the other. So, could it be, that the principle of inclusive fitness comes into play through specialisation and division of labour even in industrialised, complex societies?

Correlated and uncorrelated growth of population and economic complexity

Someone has to pay attention to a lot of laws, if he explores the connection between kinship altruism and divsion of labour. At first instance there is the law of growing complex societies: At the one end there exists for example modern India for a lot of decades in the last hundred years: Population growth without very much growth of economic and social complexity. The consequence is diminished well-being and diminished whealth of the whole society (see for example slums and so on). At the other end there are for example the western industrialized societies (Western Europe, North America, Australia): Population growth parallel to the growth of economic and social complexity (at least before the invention of the "pill" and the demographic change during the 20th century).

A naturalistic theory of division of labour has to be developed by acknowledging this two possibilities of population growth. The (fitness-)“value” of one specialist for his group, his society depends on the conditions and laws of the former growing of his group or society up to this situation, up to this state of affairs. In Western Europe there existed - for example - the “european marriage pattern”: Someone was able to have children, to  marry and to build a family, if he had a secure position, profession in the complex society of his group. By this rule or pattern population growth was connected to the growth of social and economic complexity. On the whole, growth of the population wasn't possible by diminishing the well-being of this society.

Someone has to explore, for example, how population growth in societies in pre-industrialized times was regulated. Every region, every society, every ethnie followed different laws and different time scales of its growth (or even decrease) of population due to its special historical, economic, geographic, social and cultural circumstances. In european history mostly enhanced population growth in a country correlated with the political, cultural and economic predominance, leadership of that country in that special phase of history. Often this countries and phases are regions and phases of a lot of cultural, scientific, technical, social inventions and innovations. Examples are North Italy, Southern Germany and the Netherlands in the times of the Renaissance, France in the times of Louis XIV’s, England in the times of queen Elizabeth I., Germany in the times of Bismarck. At the end of the 19th century France had a very slow population growth, while Germany had a very strong one. 

Bavaria, Austria and Switzerland

On a smaler scale: Population in Bavaria and Austria was mostly stable after the re-invention of the catholic faith and the expatriation of the protestant middle class specialists in the 17th century. At the same time the protestant regions – the Netherlands, England –, which had been able to maintain their religious freedom and protestant faith, flourished (in well-being, population and economic complexity).

On even smaler scale: Switzerland, Austria and Bavaria can be divided into different ecological zones which correlate with different economical zones. The inner alps followed different laws of population stability and growth than the pasture regions.  And the pasture regions followed different laws than regions, where cultivation of whine, vegetable and corn dominated. In the detailed circumstances of the given regional society and the given circumstances of every day life and economic conditions we have to find the hidden laws, which have to be explored to reach a formular, by which someone is able to estimate the importance and role of kinship altruism for the evolution of complex societies. In the detailed circumstances of the division of labour in the primary, the secondary and the tertiary economic sector of a given society.

I began a dissertation about this theme in 1996 at the University of Gießen, Germany. Because of a lot of circumstances the work hasn't brought to an satisfying end yet. But even 15 years later, I think that this work about the relationship between kinship altruism and division of labour in the development of complex societies in human history worldwide is still worth to be done.

______________________________________

1. Kellner, Katrin; Heinze, Jürgen: Absence of Nepotism in Genetically Heterogeneous Colonies of a Clonal Ant. Ethology, 117/2011
2. Samuel Bowles; Herbert Gintis: A Cooperative Species: Human Reciprocity and Its Evolution. Princeton University Press 2011