One of the things that’s very tricky about trying to understand the human mind is that we cannot easily remove ourselves from our own perspective. We experience our own existence, and because of that, we often make unjustified assumptions about it. One of the goals of evolutionary psychologists is to explain elements of the human mind in terms of evolutionary adaptations. In essence, this allows us to reverse engineer our minds. Once we’ve done this, we can examine the effects of our brain in light of what they are “for” as opposed to just accepting them at face value simply because they feel valid to us.
One of the fundamental assertions of evolutionary psychology is that the human mind is modular. To many philosophers and scientists, this is a controversial claim, but in many cases, the controversy is because of misunderstanding. Suggesting that the mind is modular reminds some people of “faculty psychology” invented by Franz Joseph Gall (1758-1828). Gall attempted to define the mind in terms of different faculties, or abilities. His theory was discredited and abandoned, with good reason. The current approach to mind “modules” is based entirely on evolutionary biology. When we take known principles of evolutionary theory and combine them with known qualities of various organisms, we can make predictions about how and why certain behaviors and abilities evolved. We can also, with a high degree of success, establish the order in which various mental faculties evolved.
As a simple example, let’s look at fear. We all experience fear, and we all see it in other animals. We know that fear is an ancient emotion for several reasons. First, we see it in relatively simple organisms. By all accounts, it is felt by pretty much every animal capable of any degree of emotion. Second, we see it in all the various twigs on our particular evolutionary branch. That is, since all of our primate cousins display fear, we know that fear goes at least back to all of the primate’s ancestor. Finally, we can work it out logically. Any animal, in order to survive and reproduce, has to do certain things, and we can work out the hierarchy of priority for these things using simple deduction.
Any organism, if it is to reproduce, must live long enough to reproduce. Therefore, we can deduce that predator avoidance must be the highest of priorities, for virtually all animals are threatened by predators before they are physically able to reproduce. It’s pretty easy to figure out that fear must have evolved as a means of facilitating predator avoidance. When an animal is afraid, its heart races and it receives a boost of chemicals which prepare it and enable it for maximum efficiency in the task of staying alive, whether by flight, stealth, or fight. In all cases, heightened senses and reflexes are helpful.
There’s more to this, though. Sure, we can reason that fear is a very ancient emotion, but our own fear is not simple. We experience different kinds of fear, from a subtle disquiet to a nagging urge to flee to full fledged sweat inducing terror. Fear also comes at us with different speeds. When we are startled by a sudden gruesome scene in a horror movie, we reflexively draw back, and we feel our “heart in our throats” as our heart rate increases dramatically and virtually instantly. On the other hand, when we slowly come to the realization that our spouse no longer loves us, we also gradually become obsessed with our fear of being alone again. These two emotions are actually quite different, and so we must ask how they evolved, why they evolved, and when.
The first step in this task is to see if we can work it out logically. To begin with, which is more important to a very simple animal — fast reflexes or keen judgment? It must be fast reflexes, for an animal which does not react instantly to the sudden attack of a hiding predator has no need for keen judgment anymore. Those animals which did not develop faster-than-conscious-thought flight reflexes could not have survived. So, without much mental work, we can predict that when we jump reflexively in the movie theater, we are being gripped by perhaps the oldest of our emotions. When we feel nagging disquiet, we are experiencing something that developed later.
This prediction has been verified by scientific experiment. Joseph LeDoux, an American neuroscientist, has demonstrated conclusively that the “automatic” fear response is routed more or less directly from the sensory thalamus to the amygdala, while a slower (and consequently more accurate) fear response takes a detour through the sensory cortex. Thus, when we are startled at the theater, we do not all bolt from the theater as would a crowd of a hundred startled lizards. Instead, our oldest and fastest fear response is mitigated by our slower and more accurate assessment that there is no real threat. A newer module has evolved in us. In fact, we live in a time where we are fortunate not to need our instant fear response very often. In the most “civilized” parts of the world, it’s quite possible for a human to live their entire life without once being confronted by a real predator bent on killing him. It follows then, that parts of our brain which evolved in response to predation are quite likely not particularly useful to us now, and might even drive us to do things which are irrational.
This little exercise demonstrates the current model of the “modular” brain. The mechanism for instant fear is ancient, and since we see that it functions in essentially the same way in pretty much all complex vertebrates (creatures with amygdalas) we can say that the “module” for this particular brand of fear has been in place in our brain since long before we were human. Other emotions, such as awe, must be much more recent, for most vertebrates seem completely incapable of anything approaching it. The “awe module” must exist for a reason, and it must have evolved at a time when it was an evolutionary advantage. So, the task for evolutionary psychologists is to take the results of tests in neurology, psychology, and evolutionary biology and try to piece together a testable prediction.
One of the common misconceptions of the module hypothesis is that each module is a distinct region of the brain. This is not what the hypothesis implies. Quite the contrary, actually. In order to understand why, I need to bring up another controversial topic — the brain as a computer. Many people, scientists included, get themselves quite worked up when a philosopher tries to compare the brain to a computer. Evolutionary psychologists, however, do not compare it to a computer. They simply mean something different entirely when they use the word. To evolutionary psychologists, the brain is not like a computer. It is a computer.
In this context, a computer is defined simply as anything that processes information. Of course, it must be “built” out of something, but what it is does not matter. A computer is defined by what it does, not what it is made of. So, in a very real sense, a computer is software, not hardware. When we talk about the fear response module, we are talking about a set of software that takes sensory information and processes it. Certainly our brains are substantially different than the brains of other vertebrates, but like other organs, the basic functionality has remained largely the same precisely because it is basically functional. Stomachs are good at partially digesting food, so it’s no big surprise that once stomachs evolved, they didn’t get discarded for something else entirely. Fear works wonders for keeping animals alive, so it’s no surprise that our fear response is essentially the same as that of most other vertebrates.
We must also note that differences in computing “engines” don’t matter in this context. The computational power of a computer comes from a substantially different kind of data processing than the human brain. This is irrelevant, though, as they are both still computers. Consider that both a computer and a human, through entirely different kinds of computing, can still play the exact same game of chess. So, if we are attempting to explain how the human mind works by analogy to Microsoft, we are in error, but if we call the brain a computer, we are on solid footing.
As we humans evolved, new mental abilities evolved, such as the capacity for abstract thought, for compassion, appreciation of beauty, etc. In some cases, it is apparent that entirely new physical parts of the brain were necessary before these things became possible. In others, it appears that we “discovered” new ways that existing parts of the brain could work together to do some new trick. This is all still very much a work in progress, but by all appearances, brain “modules” as they are currently envisioned are more like software upgrades than hardware, so thinking of them as distinct physical parts of the brain is incorrect. Like traditional computer software, new modules can make use of existing modules. Database software can access the internal clock or the internet communication software or the video display software. The module for abstract thinking can accesss the module for feeling love, or for avoiding pain.
In fact, we can use this model to hypothesize about various other kinds of fear we feel. When we consider a very simple, solitary animal, we realize that the only thing it needs to fear is death. It has no reputation to uphold. It cannot comprehend the future as a concept, so it need not fear it’s ultimate demise, or old age, or dying without reproducing. As we move to more complex social animals, however, we can see that certain fears would be quite useful. When a chimp of low status is observed hesitating before approaching a higher ranking female, is he feeling dread as he imagines the consequences of the alpha male discovering his indiscretion? Perhaps, but regardless of whether this is what’s happening in a chimp specifically, we can see that such a fear would be quite useful in preventing him from doing something very detrimental to his own health. Complex social animals who developed the fear of social consequences would be more functional in society, so we can easily see how fear itself could adapt, and how “software upgrades” could facilitate even more complexity, which could facilitate more software upgrades. Thus, our fear of being alone is probably a “descendant” of our fear of death, and evolved very late in our history, shortly after we developed sufficient social complexity for it to be an evolutionary benefit.
When we take this particular model of the brain and run with it, we can see that many of our human quirks make a lot more sense. Why do men still have uncontrollable jealous rage even when they know, intellectually, that there’s no reason for it? Because our brain wasn’t designed by an intelligent designer who made us perfectly for our current environment. Instead, it has been a work in progress for hundreds of millions of years, and it has undergone thousands of “upgrades” that have been incorporated into the older models. Some of what makes our minds is not perfectly suited to our current state of existence. It’s unfortunate, because the world could certainly be a lot better for us if we didn’t do a lot of things that are logically against our best interests.
The promise of science is that with a more complete understanding of just how and why we experience reality the way we do, we can begin to make objective statements about our place in the universe. We must be brave enough to give up the delusion that we are special, or that there’s some magic to any of our emotions or feelings. We must recognize the mind as part of the natural order of things, and our feelings as part of complex software. The end result, however, is that we will be better able to get what we really want in life. We can discard outdated superstition and get to the business of structuring our lives and our environments in ways that are objectively likely to produce the results we desire. Knowledge is power, and knowledge of the mind is perhaps the most powerful knowledge of all.