|Ratings are described on the Book-note ratings page.|
Michael S. Gazzaniga, Human : The Science Behind what Makes us Unique. New York : HarperCollins, 2008. xii + 447 pages, with bibliographic notes and index.
In the world of papers published in physics research journals, the research-reporting culture that is most familiar to me, there is a fine and very useful tradition of "review articles". Research on some subject proceeds and grows and the number of papers published on the topic expands and starts to get out of hand until a point is reached and some knowledgeable scientist takes on the task of organizing the literature and summarizing the knowledge and state of the art on that research topic in a "review article". Well written review articles are extremely valuable and also signal that some research topic has reached a certain level of maturity.
Human read to me in many ways like a well-written review of the current knowledge in neuroscience research and our understanding of how the brain and mind work. I say "brain and mind" not because I am a Cartesian dualist (see the discussion in the book), but to emphasize that the large part of what Gazzaniga discusses concerns levels of cognitive function that float some distance above low-level brain functions, what is known about how we think and feel and perceive the world and others in it.
The author states as one of his purposes to examine the question: "What makes us human?" I groaned a bit when I read that because there have been plenty of pointless attempts to identify some quality or other that demarcates humans from mere animals. But I was unfair to the author, who avoided my anxieties and greatly exceeded my expectations.
The great psychologist David Premack once lamented, "Why is it that the [equally great] biologist E.O. Wilson can spot the difference between two different kinds of ants at a hundred yards, but can't see the difference between an ant and a human?" The quip underlines strong differences of opinion on the issue of human uniqueness. It seems that half of the scientific world sees the human animal as on a continuum with the other animals, and others see a sharp break between animals and humans, see two distinct groups. The argument has been raging for years, and it surely won't be settled in the near future. After all, we humans are either lumpers or splitters. We either see the similarities or prefer to note the difference. [p. 7]
Although it is obvious to everyone that humans are physically unique, it is also obvious that we differ from other animals in far more complex aspects. We create art, pasta Bolognese, and complex machines, and some of us understand quantum physics. We don't need a neuroscientist to tell us that our brains are calling the shots, but we do need one to explain how it is done. How unique are we, and how are we unique? [p. 9]
I think it would be more accurate to say that he takes as his subject all of those things that go on in our heads that make us feel human. Sometimes, to clarify and amplify some ideas he does indeed compare the working of some aspect of mind to a corresponding aspect in some animal or other, but he doesn't do it merely to score points for team human. I found his account refreshing, highly readable, well organized, but comprehensive and precise in its science. Likewise I found his writing clear and precise but very engaging and readable.
Scientists are discovering that there are lots of bits of cognition and perception and understanding that are already built into our brains. Nature versus nurture? That dichotomy doesn't apply to much in any very useful way, it turns out. Evolutionary biology is providing a better way to organize and conceptualize what it being learned about the brain and what is built in to what extent and why.
We also have an intuitive knowledge of physics, although your physics grades may not reflect it. Remember that the intuitive systems make us pay special attention to things that have been helpful in survival. To survive, you didn't really need an intuitive system to help you understand quantum mechanics or the fact that the earth is however many billions of years old. It is not so easy to grasp these concepts, and some of us never do. However, when you knocked the knife off the table at breakfast, there were many aspects of physics you did unconsciously take into account. You knew it would fall to the floor. You knew it would still be there when you leaned over to pick it up. You knew it would be directly beneath you and didn't fly into the living room. You knew it would still be a knife, that it had not morphed into a spoon or a lump of metal. You also knew it wouldn't pass through the solid floor and end up under the house. Was all this knowledge learned through experience, or was it innate? Just as you understand these things, very young infants already understand these same aspects of the physical world. [p. 258]
In some ways, this book presents the latest research on the mind-body dichotomy, an issue of philosophical contention since Descartes. The basic question: is there a "mind" that is a separate entity from "brain", or is mental functioning an emergent characteristic of the physical mind. The latter is known as "reductionism", and it appears that reductionism is winning right now. At the end of his chapter "We All Act Like Dualists", in which he discusses the peculiar idea that while reductionism appears to be correct our brain seems to be set up so that we perceive its operation as "mind", he summarizes this way:
We have seen that both we and other animals share some highly domain-specific abilities, such as spooking at snakes and recognizing other predator animals. We also share some of our intuitive physics with other animals, such as object permanence and gravity, and as we have seen in previous chapters, some rudimentary intuitive psychology (TOM [i.e., "Theory of Mind"]). However, species differ in their domain specificities. Unlike other animals, we humans have an expanded intuitive understanding of physics. We understand that there are invisible forces. Current evidence suggests that we are the only animals that reason about unobservable forces. We alone form concepts about imperceptible things and try to explain an effect as having been caused by something. We also use these same abilities of reasoning about and explaining imperceptible things in the biological and psychological arenas. We understand that other living things have an invisible essence that is independent of their appearance, although we may get carried away with just what this essence is. This questioning and reasoning about imperceptible forces is a hugely significant ability. it certainly sparked the curiosity that, when coupled with conscious analytical thinking, has been the cornerstone of science, but that same curiosity has led to other, less rigorous ways of explaining imperceptible forces, such as myths, junk science, and urban legends. [pp. 274—275]
This is a large book with a wealth of information and understanding, but it's a quite manageable . I enjoyed the reading of this book a great deal, and by the end of it I found that I had learned far more than I had expected, and that far more easily. "Entertaining" and "informative", always two of my favorite attributes!
-- Notes by JNS