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August 15 - August 26, 2018
It is essential to understand our brains in some detail if we are to assess correctly our place in this vast and complicated universe we see all around us.
the existence of gods and their attendant religions is one of the most distinctive characteristics differentiating modern Homo sapiens from our hominin forefathers
As early Homo sapiens, beginning about 100,000 years ago, they developed an introspective ability to reflect on their own thoughts. Thus, they could not only think about what others were thinking but also about what others were thinking about them and their reaction to such thoughts
beginning about 40,000 years ago, we developed what is commonly referred to as an “autobiographical memory,” an ability to project ourselves backward and forward in time. We were thus able to predict and more skillfully plan for the future. For the first time in hominin history, we could therefore fully understand death as the termination of our personal existence. And for the first time, we could envision alternatives to death, including places where our deceased ancestors may still exist
For example, approximately 100,000 years ago, shells that apparently were used to make decorative necklaces first appeared. This suggests that the cognitive ability of hominins to think about what other hominins were thinking about them had matured to the point where it was affecting their behavior.
The acquisition of an autobiographical memory and other cognitive skills led to the agricultural revolution, beginning about 12,000 years ago. This brought people together to settle in villages and towns for the first time and produced a dramatic increase in the population.
As populations increased, hierarchies of the ancestors inevitably emerged. At some point, probably between 10,000 and 7,000 years ago, a few very important ancestors crossed an invisible line and conceptually became regarded as gods
Darwin wrote that he had “thought much about religion,” and in his typical telegraphic writing style, he speculated that “thought (or desires more properly) being hereditary” might be “a secretion of the brain.” If this were true, he continued, “it is difficult to imagine it [belief in God] anything but structure of brain hereditary … love of deity effect of organization.” Thus, thoughts, desires, and “love of deity,” he speculated, were all products of our brain organization.
Darwin even failed to perceive a deity in the process of creation, finding “no more design in the variability of organic beings and in the action of natural selection, than in the course which way the wind blows.”
The brain is a wondrous organ, thought to comprise 100 billion neurons and 1,000 billion glial cells.
Each neuron is connected to at least 500 other neurons, resulting in a total of 100,000 miles of nerve fibers in each brain; if laid end to end, these nerve fibers could circle the earth 4 times.
The nerve fibers are covered with myelin, a light-colored substance; because it is light in color, the nerve fiber connecting tracts are referred to as “white matter.”
Like almost all human higher cognitive functions, thoughts about gods are the product of a network of multiple brain areas. Such networks have been described as “grids of connectivity” that “allow a very large number of computational options to be associated with specific cognitive processes.”
Thus, even language, which has traditionally been thought to be localized in two brain areas (Broca’s and Wernicke’s areas), is now known to be part of a network involving at least five other areas.
Therefore, there is no “god part of the brain,” but there is a network that controls thoughts about gods and religious beliefs. This is the network of the numinous, the same network that controls the cognitive skills that make us uniquely human.
Regarding the size of specific areas, it is generally assumed in brain development that the size of a specific brain area correlates with the importance of the function served by that area. This principle has been summarized as follows: “The mass of neural tissue controlling a particular function is appropriate to the amount of information processing involved in performing the function.”
For many years, it was thought that the physical development of human fetuses precisely mirrored the evolutionary development of the species. Thus, human fetuses were said to have a tail and pharyngeal pouches that resembled the tail and gill slits of ancient vertebrates from which mammals evolved. Based on such observations, generations of biology students were taught that “ontogeny [the physical development] recapitulates phylogeny [the evolutionary development].”
Child development specialist Jean Piaget also believed that “the development of thought in children closely parallels the evolution of consciousness in our species.”
A symposium on this subject concluded that “the sequence of cognitive development in humans roughly parallels the sequence of its evolution in ancestral forms.” Thus, the cognitive development of children can be used as a clue to help reconstruct evolutionarily the cognitive development of hominins, including Homo sapiens.
Evolution of a brain occurs when the molecular structure of a gene associated with the brain undergoes an alteration that provides the organism with some reproductive advantage.
Some altered genes are disadvantageous to the organism, and these genes die out. Other altered genes provide some reproductive advantage, and these genes are more likely to be passed on. Evolution is thus figuratively the attempt of genes to get ahead in life. Darwin called this process natural selection:
Thus, the cognitive evolution of the human brain made possible the emergence of gods and civilizations. This would then be the starting point for a remarkable period of human development. In a mere 6,000 years, we would go, in the words of brain researcher Marcel Mesulam, “from the oxcart to Voyager, from the Sphynx to Rodin’s Kiss, and from Gilgamesh (by way of the Odyssey) to the Divine Comedy.”
The gods were born following a pregnancy lasting approximately two million years.
Insofar as an evolutionary origin of deities is correct, the concept of a god would not have occurred to hominins prior to about 40,000 years ago, and the gods themselves would probably not have become fully visible prior to about 10,000 years ago.
As Stephen Jay Gould noted, “We must assume that consciousness would not have evolved on our planet if a cosmic catastrophe had not claimed the dinosaurs as victims. In an entirely literal sense, we owe our existence, as large and reasoning mammals, to our lucky stars.”
“The neocortex was the key innovation of mammalian brains,” because it included six layers of neurons, compared to the three layers in the cortex of earlier animals. Since neurons are connected three-dimensionally, both horizontally and vertically, to other neurons, the additional three layers increased neuronal connections exponentially, thereby making possible the processing of much more complex information and thought.3
“Clever brains but blank minds” appears to capture the essence of Homo habilis.
However, if brain size is scaled to body size, human brains are among the largest known. Chimpanzees, for example, weigh about the same as humans, but chimpanzee brains are less than one-third the size of human brains.
A large brain is thus a distinguishing feature that sets humans apart from other primates, but brain size alone is not what makes humans unique.
The uniqueness of the human brain, rather, lies in the specific areas of the brain that are enlarged and in the intensity of the connections among those areas.
And it is probably not a coincidence that when Albert Einstein’s brain was examined after his death, his inferior parietal area was found to be “15 percent wider than controls.” This is an area that integrates visual imagery with mathematical thinking and other cognitive skills.
a study of comparative intelligence among primates and other animals reported that the two most important predictors of intelligence were the number of neurons in the brain and conduction velocity of the connecting tracts.
How did the increase occur, and why did the brain begin to increase in size at that time, after having remained relatively constant in size for the preceding four million years.
Regarding the first question, there has been an ongoing debate among scientists about whether hominin brains grew larger simply by renovating existing brain areas or whether they grew larger by creating new brain areas.
In summary, approximately two million years ago some hominins living in eastern Africa began developing larger brains and becoming significantly smarter. Given the fact that hominin brains had grown very little in size during the preceding four million years, this development was unexpected and remains unexplained.
Although Homo habilis had become smarter than other hominins living at that time, they were not aware that they were smarter.
Thus, it has been claimed with some justification that Homo erectus was “the first hominid [hominin] species whose anatomy and behavior justify the label human.”
twenty-four months, in front of a mirror, then pointed to the mirror and said, “See, who’s that?” Each child had had a red mark placed on its nose to facilitate self-recognition, and self-recognition was assumed to occur if the child touched its nose or examined it in the mirror.
No child younger than eighteen months showed self-recognition, and very few between the ages of eighteen and twenty months did. However, two-thirds of the children between twenty and twenty-four months showed self-recognition. This is also the developmental stage at which children start using personal pronouns such as “me” and “mine” and speak of themselves, as in “I throw ball.” These are indicators of emerging self-awareness.
The researchers who did the dolphin study concluded that “the emergence of self-recognition is not a by-product of factors specific to great apes and humans but instead may be attributable to more general characteristics such as a high degree of encephalization [brain development] and cognitive ability” found in all of the big-brained animals.16
Although self-awareness undoubtedly involves many brain areas, recent human neuroimaging studies have identified three areas that appear to be critical parts of the brain’s self-awareness network: the anterior cingulate, anterior insula, and inferior parietal lobule,
Perhaps the most intriguing aspect of the development of self-awareness in hominins is the possibility that self-awareness may be the product of a particular type of brain cell that arose in the course of recent evolution. These cells are commonly referred to as von Economo neurons, or VENs, after an Austrian neurologist, Constantin von Economo, who described them in 1926.
VENs have even been called “the neurons which make us human.”
The ability to think about what others are thinking—a theory of mind—would have presumably provided a major evolutionary advantage to any hominin species that acquired this skill.
Thinking about what others think, know, believe, or desire is an integral part of being human, the essence of our daily gossip and entertainment, including movies, plays, and the ubiquitous comedies and soap operas on television. An awareness of others’ thoughts and feelings is also a prerequisite for empathy, for without an awareness of others’ thoughts there can be no empathy.
damage to the prefrontal cortex may impair an awareness of others and thereby reduce us “to an almost subhuman level of functioning … devoid of what I consider our most evolved mental ability: our capacity to empathize with others.”
it has been proposed that “it is thanks to mirror neurons … that we flinch at the sight of someone else hit suddenly by a fist or a ball and wince while reading a gruesome account of torture.”
It has been recognized by several researchers that the acquisition of a theory of mind is a necessary precondition for a belief in gods.
Creating gods and attributing to them a theory of mind lead to several possible benefits. Most important, it leads to the belief that the gods can read our minds and know what we are thinking. In studies of many religions, the gods are “envisioned as possessing a deep knowing of people as unique individuals—of their ‘hearts and souls.’ ” According to Bering, this led “our ancestors to feel and behave as though their actions were being observed, tallied, judged by a supernatural audience”—in short, to greater social order.
Another benefit of creating gods with a theory of mind is that such gods are useful for explaining the unknown features of life, such as lightning being the gods showing anger, and disease being a retribution from the gods.
