Thinking Big: Gamble, Gowlett & Dunbar

by stephenpalmersf

This is one of the best surveys of the evolution of the human mind that I’ve ever read, and I’ve read a few…

Presented by Robin Dunbar (very well known in the field, and originator of the Dunbar Number), Clive Gamble and John Gowlett, Thinking Big: How The Evolution Of Social Life Shaped The Human Mind is the written culmination of a major, well-funded anthropology project called Lucy, whose intention was to investigate the social brain theory of human evolution. In a nutshell, this theory as presented in the book uses archaeological evidence, evidence from the great apes and from remaining hunter-gatherer societies to show how the need to grasp increasingly complex social interactions – represented by the Dunbar Number of the species in question – led to the evolution of the brain, of the human mind, and, although the authors almost never refer to it, of consciousness.

The Dunbar Number is the number of individuals that an individual can keep in mind in genuine social interactions, and for human beings it is around 150. This number comes up in all sorts of circumstances, showing how we, though technologically advanced, are true to our ancient roots. 150 comes up in social media, in military organisation, in English village life, and in a myriad other places. Apes have smaller numbers, chimps smaller still, reflecting the fact that their social networks are smaller.

Beginning with a survey of the anthropological field, the authors then move through our ancestors of 2.6 million years ago, through later hominids, and then through homo heidelbergensis, homo neanderthalensis and homo sapiens to show how all the evidence links together in support of the social brain theory. Human ancestors living in increasingly complex societies faced immense selection pressures from themselves, as only those able to keep in mind complex relationships were able to thrive. Interestingly, the evolutionary pressure from environmental factors (eg climate change) is comparatively played down.

There is also an explanation for one of the more puzzling events in our past, the “cultural revolution” of 40,000 years ago, when music, sculpture and art all appear in the archaeological record. This mystifying and very sudden explosion of culture is more easily explained by the preceding slow and steady emotional and psychological development of homo sapiens, which the authors point out leaves no trace, but which is clear from their evidence. Here they cite laughter, music and chanting, and family life, with only the latter leaving faint “real” marks in our environment.

This really is an exceptional book, confirming Thames & Hudson’s place in providing outstanding work in the field of archaeology, anthropology and human evolution. The authors should be proud of their achievement.