The Biological Basis of Social Behavior

This post is a review of the book Sociobiology by the Harvard entomologist E. O. Wilson. It was originally published in 1975, to acclaim and controversy, and is considered a landmark work which established the biological and evolutionary basis of behavior in animals (including humans).

It is about 700 pages long, and in spite of not being an expert in biology, I found it remarkably accessible. The book lays out in great detail, and with an abundance of examples, the author's thoughts about the genetic basis, and evolutionary modification, of social behavior. It is broadly divided into 3 main sections. Rather than tackle the impossible task of detailing the contents, I will give a general outline and mention the parts that stood out to me:

1. Fundamentals: This part treats the basic factors behind the need for, and evolution of, social evolution. Wilson recognizes that the basis for existence of an organism is simply its role as a conveyor of its DNA (a modern, information-theoretic view considers DNA to be the software, which is refined by evolution, and our bodies to be the hardware, which is recycled). And evolution has shaped our interactions - which occur through the emotions and instincts (love, hate, guilt, fear, desire, etc.) - to help perpetuate the organism during its lifetime with minimal damage to the DNA and maximal chances of propagating it.

   
   

   Therefore, the central problem of sociobiology, says Wilson, is the tradeoff - that every organism which does not live by itself has to negotiate - between selfishness (promotion of the self) and altruism (promotion of society).

   
   

   With this starting point, Wilson defines the units of society (e.g. individual, troop, band, population); and the kinds and degrees of sociality (e.g. permeability of status, amount of connectedness, direction of information flow). With these in place, he goes into the details of population dynamics (mating, birth, feeding, predation, cannibalism, disease, death, extinction) - there's a good number of mathematical equations here.

   
   

2. Dynamics: This part gives details on the various kinds of interactions that prevail in a social system and their mechanics - e.g. communication; leadership and dominance hierarchies; parasitism, altruism and cooperation; courtship, sex and polygamy; parental care and division of labor; competition, territoriality and aggression (apparently there is an optimal level for each species); play, etc.

   
   

3. Applications: This part starts by addressing the specific social behavior of bacteria and then successively moves through societies of insects, cold-blooded vertebrates (frogs and reptiles), birds, ungulates (hooved mammals) and elephants, carnivores, the nonhuman primates (monkeys and apes), finally making its way, in the final chapter, to humans. Surely a grand sweep!

   
   

   Wilson concludes that 4 groups have reached the peak of sociality: the colonial invertebrates (mosses and sponges), the social insects, the nonhuman primates, and human beings. However, he notes that the altruism and cooperativeness seem to go down as the complexity of the individual organism increases - doesn't put us on top of the list! It is actually the sponges, he says, which have evolved into nearly perfect societies.

Summary

This is a book conceived and written on a grand scale. I do not think it can be digested, even by a professional biologist, in one reading. It is a storehouse to which one can return repeatedly for information, understanding, and stimulation.

Throughout the book, of course, are incredible examples from the extravagant beauty, terror, and diversity of nature: the fluidity of membership in chimpanzee groups (ex-members often kill present members and vice versa); the identification of seven different species of spiny lizards by their females (by the frequency and amplitude of head bobs); the differences in the human vocal apparatus, compared to the chimpanzees, that enable speech; the potty-training that tree shrews make their young go through...

Wilson wrote (he passed in 2021) with clarity and culture, quoting at depth from the sciences, arts, literature, history and psychology with ease. He won two Pulitzers for his non fiction writing. This book is a grand sample of that legacy.