The Shrinking Human Brain I have recently finished reading an interesting book, titled “The Domesticated Brain”, written by Bruce Hood, a British Academic Psychologist. The subject matter of this book served as a reminder of a previous account I have previously posted on this page (see the article “Read this if you think size matters”, originally posted 15 August 2013). I have attempted then to briefly describe the processes involved in the evolution of mankind from the early gorilla-like hominid species to the current form and function we all know. I deliberately emphasised the progressive increase in the shape and size of the skull in order to highlight the importance of the brain in the success of the Homo sapiens over others, namely the Neanderthals. The punch lines that account are as follows: “The Neanderthals inhabited Europe at the same period when the early Homo sapiens were in Africa and Asia. Both species had significantly larger brains than their predecessors, the Homo erectus. However, the Neanderthals, who shared 99.7% of our genes, had larger brains and yet became extinct while the Homo sapiens dominated the Earth. The main reason for the Homo sapiens success is their superior brain giving them (us) better chances to intelligently cope with the hardship of diverse changing circumstances.” The average human brain 20,000 years ago was 10% larger than it is today. Some anthropologists suggest this marks decline in our intelligence. However, the author of “The Domesticated Brain” is of the opinion that shrinkage can be explained by our social evolution – I totally agree with this. He says: “We have been self-domesticating through the invention of culture and practices that ensure that we can live together.” He also argues that animal species that has been domesticated by man has lost brain capacity as a result. I am neither in a position nor aim to argue for or against every example given the book and/or the author’s own reasoning. However I would like to specifically agree with the suggestion that the social behaviour is the key for all human successes. I wouldn’t be writing all this at all if I don’t have my own views regarding the topic raised. I personally believe that any reduction in brain size as quoted is more than likely to have been related to our social evolution and for the reasons explained below. I also believe that 10% reduction in brain size has not led to reduction in the intellectual ability of mankind. Contrary to that, we are evidently more advanced today than any other human being ever lived before us. The starting point in support to my argument is that survival of an individual is better served if he or she is in a company of other people, working together for the benefit of the whole group. That is how mankind survived and progressed to where we are now. Humans went through various stages of group collaboration; from small packs of hunters, through small settlements, then bigger ones with other related settlers, to formation interdependent villages and cities, and eventually to nations with defined boundaries. This social journey was accompanied by evolution of languages, better communications, distribution of tasks, spread of knowledge, specialisation, development of skills and innovation. As communities grew bigger, rules were invent to define the relationship of its members, moral values were created, and emergence of leaders and ranks within the society also occurred. Such social progression meant that individuals became more dependent on their respective social structures for mutual benefit and individual survival alike. In my opinion this dependency alone can account for the apparent progressive shrinkage of human brain over the said twenty thousand years. The dependency on social structures meant that the more primitive of the brain functions, once needed for the isolated individual survival, became redundant and gradually demised. The higher brain functions that are necessary to secure our places within the social structure remained intact, and so our intellect. Working together proved to be beneficial for everyone. However, there is a downside for every success, and this one is really too serious to overlook. As it is now, we live in world where human beings are pigeon-holed into groups according to skin colours, tribes, religions, political ideology, nations, or any other group or sub group one can think of. The social dependency which is meant to be beneficial to mankind is also responsible for prejudice and often led to blind allegiances to the group values, which can only too easily manipulated by unscrupulous leaders; political and spiritual alike. Rational thinking seems to have ceased by many and the burden of individual morality appear to have shifted to the moral values of the group, whether these are right or wrong. To such people all horrific acts; murders, massacres, genocides, and wars became acceptable if committed on the group’s behalf. Excluding natural disasters, I have great difficulty in identifying a single reason for any of the dark events in human history, past and current, that cannot be explained by blind allegiances to prevailing social structures with associated decline in moral values. We may not be physically regressing towards the Homo erectus stage of the evolutionary path but we are mentally facing that way and could be heading that direction if we don’t steer our moral values in the correct direction.
Posted on: Wed, 16 Jul 2014 02:37:17 +0000