“For the scientist who has lived by his faith in the power of reason,” wrote Robert Jastrow in God and the Astronomers, “the story ends like a bad dream. He has scaled the mountains of ignorance; he is about to conquer the highest peak; as he pulls himself over the final rock, he is greeted by a band of theologians who have been sitting there for centuries.”
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Jastrow’s words come to mind whenever I hear about professional scientists being obliged to abandon, or at least to seriously modify, their Darwinian assumptions. From cutting-edge work in genetics to the latest discoveries in astrophysics, the evidence is increasingly pointing to one fact: Darwin was wrong.
This has been impressed upon me recently, as I have been studying the way culture affects the human brain. Contemporary neuroscientists have been making some fascinating discoveries about the way our cultural preoccupations and artifacts alter the physiological structure of our brains, and, once again, Darwinian orthodoxy is being compelled to yield to new findings.
Dogs, Pigeons & Beethoven
Let’s begin with a fact that no one disputes: different species have brains suited to the demands of their kinds; brain structures differ among species according to need. The brains of dogs, for example, have a greater facility than human brains for processing smells, because dogs need a high level of olfactory acuity to survive in the wild. Indeed, the odor-processing region of the canine brain is about four times the size of the one in your brain or mine. Or again, the brains of pigeons have the ability to process magnetic information, which they use to navigate vast distances accurately, whereas our brains do not have this faculty since we don’t need it; we can create and use navigational instruments.
On the other hand, human brains possess structures that allow us to do all sorts of things that dogs and pigeons cannot, such as to reason analytically and to appreciate art. It isn’t that no one has ever tried to teach a pigeon how to do calculus or to relish the glories of the way Beethoven expanded the sonata-allegro form; it’s that no one ever could; the pigeon’s brain is structurally incapable of apprehending these things.
Sea Gypsies & Taxi Drivers
Interestingly, what is true as regards the brain structures of different species is also true regarding the brain structure of different groups of human beings—though only up to a point. Still, this fact raises some questions.
Take, for example, the Sea Gypsies, a maritime tribe of people living off the coast of Thailand. These people have brains that facilitate exceptionally keen underwater vision. Not only can their brains override the reflex that normally controls the shape of the pupil, enabling a Sea Gypsy to constrict his pupils by 22 percent, but they can also accurately compensate for the refraction that occurs when light passes through water. To expect a non-Sea Gypsy like myself to exhibit the same facility would be like expecting a dog to deliberately bark in F major or a pigeon to coo in D minor.
So how is it that the Sea Gypsies have this amazing ability? According to standard Darwinian theory, the explanation goes something like this: over thousands of years, our genetic makeup gradually changes to conform to the demands of our environments, leading to appropriate changes in the structure of our brains. Genes that have survival value will be perpetuated through succeeding generations, while those that do not will tend to die out.
Thus, according to the Darwinian narrative, because Sea Gypsies spend much of their lives around the water and survive by diving to great depths to harvest food, their genetic makeup gradually came to include these unique capabilities, just as the genetic makeup of dogs came to include exceptional odor-processing faculties. In both cases, we are observing the results of gradual adaptation spanning thousands of years.
But, as I suggested earlier, this evolutionary narrative has recently had to be abandoned by professional neuroscientists. We now understand that these types of variations in the brains of different people groups have nothing to do with genetics at all. The physiological structure of our brains, including hundreds of thousands of neuro-connections, do evolve to adapt themselves to our natural and cultural habitats, but this evolution occurs within a single lifetime without leaving a footprint on the genetic code.
This was demonstrated through a study of brain scans done on London taxi drivers in the late 1990s. Researchers found that, in the cabbies, the posterior hippocampus, a part of the brain that stores spatial representations, was considerably larger than in non-cab drivers. Now, clearly, a London taxi-driver’s genetic make-up is not fundamentally different from a London mechanic’s or a London web designer’s, yet there are very clear structural differences in their brains. How did this come about?
Well, it isn’t rocket science. Your brain is like a muscle: the more you train it in a particular skill—like learning a language, mastering a musical instrument, navigating London, or hunting underwater with your eyes open—the better it gets at that skill. And just as regular bench-pressing causes changes in the structure of your pectorals, deltoids, and triceps, so, too, continued exercise of your brain “muscles” causes actual changes in the neurocircuitry of your brain.
Of course, not everyone can master every skill, and so not all parts of one’s brain will get equal amounts of exercise. In the London cabbies, who had memorized hundreds of maps and street names, it was noticed that, as the part of the hippocampus concerned with spatial representations had grown, it had expanded into adjacent neuro space, namely, the anterior hippocampus, which is below average among taxi drivers. Similarly, as a blind person exercises his hearing to compensate for his lack of sight, the audio-processing part of his brain will “move in” to the empty visual cortex, which explains why blind people can listen to audio books at phenomenal speeds. In this respect, the brain can be compared to a large parcel of real estate; when one plot is expanding, it will appropriate less-used or unused plots.
This may seem obvious, but until recently this whole area was hotly disputed. Ever since Descartes, conventional brain science has been dominated by the theory of “localizationism.” This theory sees the brain as a complex machine made up of innumerable parts, each of which performs a specific function and only that function. So if one part (e.g., the vision-processing part) were damaged, it would simply be dormant; it could never be taken over by another part (e.g., the sound-processing part).
But scientists have recently begun to understand that the brain is much more malleable and flexible than the theory of localizationism gives it credit for. So they now use the term “neuroplasticity” to describe the brain’s almost infinite potential for adaptability.
It is precisely this adaptability that has rendered void so much of the standard Darwinian narrative.
In his bestselling book The Brain That Changes Itself, Norman Doidge writes:
Up until the discovery of neuroplasticity, scientists believed that the only way that the brain changes its structure is through evolution of the species, which in most cases takes many thousands of years. According to modern Darwinian evolutionary theory, new biological brain structures develop in a species when genetic mutations arise, creating variations in the gene pool. If these variations have survival value, they are more likely to be passed on to the next generation.
But plasticity creates a new way—beyond genetic mutation and variation—of introducing new biological brain structures in individuals by non-Darwinian means. When a parent reads, the microscopic structure of his or her own brain is changed. Reading can be taught to children, and it changes the biological structure of their brains.
Culture over Genetics
The picture that is emerging is that the activities we engage in, from hunting under water to driving taxis to simply listening to someone read aloud, cause changes in our brains. Evolution happens, but it happens within each one of our brains every second that we interact with our surroundings. If a person’s surroundings suddenly appeared upside down—as they would if he put on glasses that reversed everything—his brain would learn to adjust to this and flip everything the other way round again (an experiment that has actually been performed with fascinating results).
Thus, if a child from a Western culture were adopted by a family of Sea Gypsies, there is every reason to expect his brain to develop the same unique capabilities as a native of that culture, just as adopted children can learn to speak their parents’ language fluently and without an accent.
Thus, what evolution tried to explain in terms of genetic mutation is better accounted for by the influence of culture on the neuroplastic brain. Whether we are immersed in a culture of driving, like the London cabbies, or a culture of underwater swimming, like the Sea Gypsies, the physiological structures of our brains will be adapted accordingly.
Culture also affects our brains in less obvious ways. Consider that we tend unconsciously to accept as “normal” that which our culture regards as normal. “Cultural differences,” Norman Doidge writes,
are so persistent because when our native culture is learned and wired into our brains, it becomes “second nature,” seemingly as “natural” as many of the instincts we were born with. The tastes our culture creates—in foods, in type of family, in love, in music—often seem “natural,” even though they may be acquired tastes. The ways we conduct nonverbal communication—how close we stand to other people, the rhythms and volume of our speech, how long we wait before interrupting a conversation—all seem “natural” to us, because they are so deeply wired into our brains. When we change cultures, we are shocked to learn that these customs are not natural at all.
The Sinister Side of Plasticity
There is also a sinister side to neuroplasticity, which Norman Doidge discusses as well. Not only can culture exercise a positive influence on our neuroplastic brains, but it can also affect us in harmful ways. If mastering a language or the use of a new tool opens up new neuro pathways in our brains, subversive cultural influences can do the same.
Hence, in a given environment, we may find ourselves so immersed in certain wrongful practices or assumptions that immorality can start to feel normal and righteousness weird, thus underscoring William James’s point that “there’s nothing so absurd but if you repeat it often enough people will believe it.”
The industries of advertising, media, and entertainment provide numerous examples of this. Without understanding how easily our brains can be influenced by these industries, we can easily miss the real dangers they present. The threat comes not so much when the truth is directly attacked as when we are told in hundreds of subtle and implied ways what “the good life” is all about and what we should do to achieve it.
Given the way our flexible brains tend to rewire themselves to adapt to our environment, it is easy for us to “catch” the assumptions of false worldviews without realizing we have done so, just as a child learning a language will pick up the right accent without even thinking about it. David Wells grasped this well when he wrote that “worldliness . . . is that set of practices in a society, its values and ways of looking at life, that make sin look normal and righteousness look strange.” The changes in our brains wrought by these societal influences often occur deep below the surface of our conscious awareness, leading us to hold pre-reflective assumptions that are, to quote Herbert Schlossberg,
more powerful than assertions, because they bypass the critical faculty and thereby create prejudice. . . . The simple act of listening to an argument is almost enough to engage it. . . . That bypassed assumption is the pocket of enemy soldiers that was ignored in an effort to engage the main body of the adversary, and it lies in wait to strike from the rear. The false assumption is additionally beguiling because it often appeals to one of the worst instincts—the desire to be fashionable or at least to avoid being associated with the unfashionable or unpopular.
So what are some of the false assumptions that our culture beguiles us with? Here are a few, chosen almost at random:
• Elderly people are boring.
• In music or art, beauty is merely in the eye of the beholder.
• Women who are modest are uncomfortable with their bodies.
• It is unmanly for men to show emotion.
• Having high standards is “legalistic.”
• What’s important is what has happened recently.
• It’s a sign of maturity to be able to watch sex scenes and gratuitous violence in movies without being affected by it.
• It is undesirable for a woman to gain weight as she gets older.
These are only a few examples, and in fact the most subversive assumptions are those that cannot even be expressed propositionally. The power of assumptions like these is that they are usually felt long before they are thought, as our brains have subtly been rewired without our consciously realizing it.
Showing the Sweetness
Needless to say, it is not always a bad thing for our culture to rewire our brains, and many such rewirings are harmless or morally neutral. Few would want to argue, for example, that it is either good or bad that our society has trained us to dislike the smell of body odor. However, when cultural assumptions conflict with our fundamental beliefs about the world, it is crucial to exercise critical discernment and to beware of the potential to unthinkingly imbibe the assumptions of our age.
There is an important application here for parents. Because the most basic impulses of our thinking are “caught” rather than “taught,” parents seeking to transmit a certain worldview to their children must give attention to what is conveyed in the atmosphere in which young people find themselves. The messages about the good life that are unconsciously inscribed on our children’s minds in their home life, their school experiences, and the culture around them are incredibly formative—even more formative than what they are taught didactically.
As this suggests, understanding the effects of cultural learning on the human brain has enormous implications for Christian apologetics. Our apologetics must be not merely intellectual but also cultural. We must work to transform the rhythms and practices of our culture—including the culture of our Christian communities—to reflect the beauty and desirability of Christ.
Aleksandr Solzhenitsyn once noted, “In vain does one repeat what the heart does not find sweet.” It is not good enough simply to prove to someone that Christianity is true; if we are to have an impact for Christ, we must also show that the faith is sweet. One way we can do this is through cultural expressions that embody that sweetness, that show that Christianity is not only true, but also lovely and desirable. •
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