Friday, October 7, 2011

Evolution of religion, part one.

The following entries are from the Revised Edition of the Encyclopedia of Evolution, which will be published online by Facts on File in 2012. I have taken them from the entry, “religion, evolution of.”

Homo sapiens is a religious species. This is one of the few behavioral universals of the human species. Though there is individual variation in the strength of this trait, no society is without it; those that tried to eliminate it have failed. Religion appears to be ineradicable. There is clearly no biological basis for particular religions, but it is likely that there is a biological basis for the capacity for religion.

Neandertals apparently did not have religion. The contrast between the religious artifacts of Homo sapiens and their absence in Homo neanderthalensis in their regions of overlap could hardly be greater. While Homo sapiens had intricate burials (a burial of two children in Sungir, Russia, contained 10,000 shell beads each of which took from one to three person hours to prepare), Neandertals apparently dug the shallowest possible graves to keep the body from stinking. The Shanidar burial of a Neandertal with flowers, even if it is confirmed, is a rare and isolated instance. Neandertal pendants associated with the Châtelperronian culture have been mostly dismissed as imitative of the Aurignacian culture of the Cro-Magnon, and even if they were not, their connection with religion is unclear. Neandertal caves totally lack the wall art that abundantly and resplendently represents Cro-Magnon religious experience. Anthropologist David Lewis-Williams calls Neandertals “congenital atheists.” Yet Neandertals had brains at least as large as those of modern humans. Other groups of H. sapiens, all over the world, had a similar abundance of religious practice.

What is Religion?

Religion is not a single thing; it is a set of memes that have taken up residence in human minds. These memes use human minds, words, and actions as a way of propagating themselves. The human brain is the hardware, and religious memes the software. Many scientists have reified these memes and the physical attributes that they use into a single concept. Therefore when scientists say that religion is universal among humans, they mean that every human has the mental components that can or do harbor and propagate religious memes, and that some of those memes can be found in every culture and every individual. They cannot say that natural selection has or has not favored religion as a whole. Natural and sexual selection clearly controlled the origin of the brain processes of which the religion memes make use. Social evolution has promoted religion in most cultures at most times, often to the benefit of powerful individuals who use it to dominate others.

The Brain: The Hardware of Religion

Human brains increased in size over evolutionary time for numerous reasons, including the mastery of technology, sexual selection, and social interactions. Religion probably had nothing at all to do with it the evolution of intelligence. But as the brain increased in size, it was not just the parts of the brain that conferred social and technological skills that increased; the whole brain increased in size, including the parts associated with the following capacities:

• Sexual ecstasy. Humans have a highly-developed capacity to experience sexual ecstasy. Religion, like orgasm, can create a feeling of transcendence (ex- means out of, stasis means place).
• Loss of the awareness of having a defined body. The sensation of having a defined body is something that the brain creates. Some kinds of strokes cause their victims to experience reality as a stream of sensations, without an awareness of embodiment. In ancient times, some people may have experienced head traumas, oxygen deprivation, starvation, or dehydration, which opened them up to a disembodied sensation, or they may have induced these feelings by meditation. This is one of the elements of religious experience, commonly reported by people who have a well-developed ability to meditate.
• Altruism. Altruism is one of the most pervasive human characteristics, and one for which religion clearly provides an outlet. One of the principal components of altruism is guilt, which reinforces the likelihood that people will act altruistically.
• The need for an authority figure. Humans appear to have a psychological need for an authority figure whose goodness they do not question. In adults, this may be a vestige of a child’s worship of parents.
• Awareness of death. Natural selection favored the evolution of intelligence, and one of the side-effects of intelligence is the ability of a person to understand that he or she will die, and the possibility that he or she will be preoccupied by it.
• Agency. Very young children do not display feelings or awareness that can easily be described as religion. They do, however, always have the capacity for agency attribution. When something happens, they think that someone has caused it to happen. The wind blows because someone makes the wind blow. If they experience pain, it is because someone is hurting them.

Religion makes use of all of these brain elements. Specific areas and functions of the brain have been implicated in the mystical, religious experience. Neurologists Andrew Newberg and Eugene d’Aquili have been particularly active in researching the brain activities associated with religion. They point out, for example, that when humans enter an altered state of consciousness, the orientation association area of the brain (which in the left lobe is associated with the sensation of having a limited body, and in the right lobe with the sense of space that a person occupies) contribute to out-of-body experiences.

Religion is not pathological, but brain pathologies can help scientists to understand its neurological basis. Stimulation of the right temporal lobe by electrodes (or pathological stimulation by epilepsy) produces experiences closely paralleling the near-death experience of passing through a tunnel towards the light. Similar effects are also produced by the drug ketamine.

Announcement: On my other blog I begin an October series about the dinosaur footprints in the bed of the Paluxy River in Texas. On my YouTube channel, Darwin visits these dinosaur footprints.

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