AFTERWORD - Human: The Science Behind What Makes Us Unique - Michael S. Gazzaniga

Human: The Science Behind What Makes Us Unique - Michael S. Gazzaniga (2008)


This is my simple religion. There is no need for temples; no need for complicated philosophy. Our own brain, our own heart is our temple; the philosophy is kindness.

Tenzin Gyatso, the fourteenth Dalai Lama

As long as our brain is a mystery, the universe, the reflection of the structure of the brain, will also be a mystery.

Santiago Ramón y Cajal, Spanish physician and Nobel laureate

LONG BEFORE I BEGAN THIS BOOK, AS I WORKED MY WAY UP through my classes, I posed the question to various family members and friends, “In what ways do you think humans are unique?” Years ago, I did a more formal version of this tactic. I wrote many of the leading thinkers of America and asked them, since they made decisions every day about worldly matters, what was their theory about the nature of man? This was done in preparation for my book The Social Brain. It was a fascinating exercise and proved productive. So why not try it again, this time with family and friends of both sexes and all ages?

Naturally, I thought I might actually start the book with these suggestions and either verify them or shoot holes in them. Most people told me they would think about it and get back to me. I filed away the few responses I received. I haven’t looked at them again until now, wondering how they matched up with the various ideas and facts I had come across.

It seems, even though the responses were few, I received a rather good cross section. Although they weren’t all written in the same lingo, in one way or another, several of our unique abilities were identified. Leave it to a therapist to identify the moral emotions of guilt and shame. A teacher suggested that humans are the only animal to actively teach their young. An accountant mentioned mathematical abilities, and a five-year-told me, “Animals don’t have birthday parties for themselves, you have to give them one.” A teenager, fresh out of high school, said other animals don’t starve themselves by dieting, don’t accessorize, and don’t have tummy tucks. Other unique abilities mentioned were that humans could voluntarily recall an enormous amount of stored information, could play and write music, had language and religion, believed in an afterlife, played team sports, and were disgusted by feces.

There were also the people who weren’t altogether impressed with humans. Some said that humans were not unique. One response from the obstetrics clinic was, “I think at the core humans are no different from animals. We all have the bestial urges of expanding our hunting range, controlling resources, and spreading our DNA. The need to ask the question separates us, but the reality of our behavior is not so very different from our animal counterparts.” Or from an ornithologist after a hard day: “Humans are self-centered egotists who take advantage of other humans, other animals, and the lands they inhabit for what they think suits them and without considering how their actions affect other living things—plant and animal.” Of course this describes all the animals that she loves, too. A hawk is not concerned about the mouse’s family when it swoops in for lunch. A beaver is not concerned about the effects of the dam it is building on the creek.

I was also given some suggestions that sounded promising but then later proved to be a bit off. An anthropologist suggested that humans were the only animal with incest taboos. As we saw, there is some of this going on with chimpanzees. That surprised me, too. A marine biologist suggested that humans were the only animals that can change natural selection. I didn’t discuss something known as niche-construction theory, which suggests that animals actually do cause changes to their niche that affect natural selection. However, humans are the only animals consciously tinkering with their DNA via technology. Along these lines, another observation was that humans have been able to separate sex from reproduction through technology.

Obviously, people were looking at the question from their own perspectives, the jobs they did, and their personal interests. I guess I should have quizzed a chef, because no one mentioned cooking. It was interesting that no one brought up the basic question concerning whether animals understood that other individuals had thoughts, beliefs, and desires, or thought about their own thoughts. No one wondered if other animals’ consciousness was different from our own, which is indicative of how strongly we humans anthropomorphize, lavishing theory of mind on other animals. Also, no one mentioned that humans alone thought abstractly, had imagination, or thought about, reasoned about, and explained imperceptible forces, causes, and effects. Nor did anyone suggest that we are the only animal that could separate pretense from reality, use contingently true information, time-travel in our imaginations, or manifest episodic memory. And no one realized that we are the only animal that can delay gratification by inhibiting our impulses over time. It was not surprising that no one mentioned we were the only animal that frequency matched. Irritatingly enough, however, not one person in my family mentioned the left-brain interpreter. What is up with that?

On the evolutionary tree, we humans are sitting at the tip of our lonely branch. The chimps have their own branch with the bonobos sprouting off it, and a common ancestor links us. We have the same roots as all living organisms. That is why those who don’t see much difference between humans and animals have a strong footing. All those similarities are there. Our cellular processes depend upon the same biology, and we are subject to the same properties of physics and chemistry. We are all carbon-based creatures. Yet every species is unique, and we are too. Every species has answered the problem of survival with a different solution, filling a different niche.

One other comment that I received was that humans don’t have a built-in defense mechanism, like fangs or claws. We do pack a punch with our fists, but we also have, as Inspector Poirot likes to point out, the little gray cells. We Homo sapiens entered a cognitive niche. We have done all too well without the fangs and claws. Without the changes to our physical structure, we could not have developed the abilities that we have. We needed to have free hands and fully opposable thumbs and a larynx and all the other changes to our body before we could acquire many of our unique abilities. Yet there were more than just the physical changes.

As we have seen, we do have physically big brains, but that is not the whole story. The Neanderthals had a bigger brain than we but did not develop the same advanced artifacts as the upstart Homo sapiens. Will we ever know what happened and how the change came about? This question haunts paleontologists such as Ian Tattersall. He just wants to know: unrequited curiosity. Many try to define our uniqueness in terms of quantity versus quality. Are we on a continuum, as Darwin thought, or was there some big leap? By studying our closest living relatives, the chimps, we have learned that our brains are both quantitatively and qualitatively different. We have a bigger brain, and some of the parts are different. But I think the crucial difference is that we aren’t hooked up the same. Everything has been tweaked and interconnected. Feedback loops have been formed that allow rumination and inhibition and may be the basis for our self-awareness and consciousness. The corpus callosum has allowed more punch per cubic inch of brain, eliminating redundancy and allowing the two hemispheres to specialize and increase efficiency. Specialization appears to have run rampant, creating various modular pathways. Our mirror-neuron systems seem to be into everything, providing us with imitative abilities that may be the basis of our social abilities, our learning, our empathy, and perhaps our language. And the story of those connections is continuing to unfold.

Humans are actually just getting a toehold on understanding their abilities. Whether we have the brain capacity to assimilate all the information that is being collected is questionable. Maybe those people who see humans as only slightly different from the rest of the animals are right. Just like other animals, we are constrained by our biology. We may not have the capacity to be any better than their worst appraisal. But the ability to wish or imagine that we can be better is notable. No other species aspires to be more than it is. Perhaps we can be. Sure, we may be only slightly different, but then, some ice is only one degree colder than liquid water. Ice and water are both constrained by their chemical composition, but they are very different because of a phase shift. My brother closed his list of differences by saying, “Humans will sit behind a computer and try to figure out the meaning of life. Animals live life. The question is: Who is better off, the human or the animal?”

That’s enough! I am going out to tend to my vineyard. My pinot grapes will soon be producing a fine wine. Am I ever glad I am not a chimp!