There are many scientific theories as to why what today we term religion seems to have been present in almost all human cultures. Some argue that religion is an evolutionary by-product of parts of the brain that developed for entirely different reasons. Others have suggested that collective religion in particular seems to improve the brain functions of its participants, so that any neural predisposition towards religion is more likely to be passed on genetically.
However, it is difficult to apply these theories to the people of the Mesolithic, partly because we cannot assume that just because they were anatomically identical to us, their brains functioned as ours do. In fact, they almost certainly did not. We now know that the brain forms new neural pathways and reorganizes trillions of of synaptic connections throughout its owner’s life in response to external stimuli. For example, the area of the brain governing spatial awareness is often larger in taxi drivers because they have to be able to navigate many complex routes through large cities, the part of the brain used in learning a language is larger in bilingual people, and so on. At the same time, it seems that if certain brain functions are not used, the relevant synapses will change so that the brain can no longer perform those functions to the same extent, or at all. This may account for the familiar feeling of having lost the ability to do mental arithmetic through reliance on calculators. It may also have been what Julius Caesar referred to over 2,000 years ago when he wrote of Druids refusing to use writing for fear of weakening their astonishing powers of memory.
It is therefore reasonable to assume that the hunter-gatherers of the Mesolithic, in order to survive, must have had far better memories than we do today, as well as far greater spatial awareness. What difference this may have made to the way in which they saw themselves and the world cannot be known, but the brain’s sense of self may be another factor. Psychological and neurological studies indicate that our sense of ourselves and of others is the result of a brain function that evolved to help us co-exist with each other, and that our notions of self are therefore not fixed but are individual ideas that we continually test and revise according to experience. If so, ideas of the self are likely to be different in cultures in different environments with different stimuli, such as those of the Mesolithic.
This may explain why the visual sense of self that our brains develop is perhaps more fluid than we might assume. In the optical effect known as Troxler’s Fading (after the Swiss physician who first studied it), staring at a fixed point within other peripheral images – for example, a red dot within a blue circle – results in the peripheral image first fading, then vanishing.
The effect is caused by the brain deciding that because no attention is being paid to the peripheral image, the neurons responsible for perceiving it need no longer do so, so that it becomes invisible until attention is switched back to it. However, other studies have shown that the brain does something similar when the fixed point being studied is not a red dot within a blue circle but part of a human face. The effect is different, possibly because substantial parts of the brain deal with facial recognition and so cannot easily discard data concerning it. Yet the brain will still try to discard visual stimuli that at that moment are apparently far less important than the point of focus. The practical effect is that someone staring at a fixed point in the reflection of their face in a mirror will within seconds seem to see the rest of their face either vanish or turn into other images, sometimes the features from the faces of other people, or even of animals. Although it’s an interesting experiment, most people’s visual sense of themselves is too strong to be seriously affected by it. Yet it may be worth remembering that today, the visual sense of self is usually first created, then continually reinforced, by the sight of our own images in highly reflective mirrors and photographs, neither of which existed until relatively recently.