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

From the Publisher

One of the world's leading neuroscientists explores how best to understand the human condition by examining the biological, psychological, and highly social nature of our species within the social context of our lives.

What happened along the evolutionary trail that made humans so unique? In his widely accessible style, Michael Gazzaniga looks to a broad range of studies to pinpoint the change that made us thinking, sentient humans, different from our predecessors.

Neuroscience has been fixated on the life of the psychological self for the past fifty years, focusing on the brain systems underlying language, memory, emotion, and perception. What it has not done is consider the stark reality that most of the time we humans are thinking about social processes, comparing ourselves to and estimating the intentions of others. In Human, Gazzaniga explores a number of related issues, including what makes human brains unique, the importance of language and art in defining the human condition, the nature of human consciousness, and even artificial intelligence.

The New York Times - Daniel J. Levitin

Gazzaniga, a cognitive neuroscientist at the University of California, Santa Barbara (and one of the inventors of the field), takes us on a lively tour through the latest research on brain evolution.

Publishers Weekly

As wide-ranging as it is deep, and as entertaining as it is informative, the latest offering from UC-Santa Barbara neuroscientist Gazzaniga (The Ethical Brain) will please a diverse array of readers. He is adept at aiding even the scientifically unsophisticated to grasp his arguments about what separates humans from other animals. His main premise is that human brains are not only proportionately larger than those of other primates but have a number of distinct structures, which he explores along with evolutionary explanations for their existence. For instance, a direct outgrowth of the size and structure of the human brain, along with their origins in the complexity of human social groups, was the development of language, self-awareness and ethics. (Gazzaniga offers some surprising comments on the evolution of religion and its relation to morals.) Throughout, Gazzaniga addresses the nature of consciousness, and by comparing the intellectual capabilities of a host of animals (chimps, dogs, birds and rats, among others) with those of human babies, children and adults, he shows what we all share as well as what humans alone possess. (July)

Gregg Sapp - Library Journal

Where the brain is concerned, does size matter? Until recently, research into the evolution of hominid species into Homo sapiens has focused on physical features, with the study of cognitive evolution limited to speculating how brain size affected psychosocial capacities. Advances in modern neuroscience reveal that the unique capabilities of the human mind are only possible through much more complex and subtle differences than just size. Neuroscientist Gazzaniga (The Ethical Brain) discusses the brain functions underlying the defining characteristics of what makes us human: arts, ethics, empathy, conceptual thinking, and self-awareness. The first three parts of his book ("The Basics of Human Life," "Navigating the Social World," and "The Glory of Being Human") explore the neural mechanisms that make humans different from other species. The final section, "Beyond Current Constraints," speculates freely on future brain evolution, both natural and technology-enhanced. Although the text can be a bit dense in places, readers attracted to this subject are generally more than willing to invest the neural energy required to follow it and will be rewarded for doing so. Recommended for academic and larger public library science collections.

Kirkus Reviews

One grand search engine for all the qualities that make Homo sapiens different from other species. Cognitive neuroscientist Gazzaniga (Psychology/Univ. of California, Santa Barbara; The Ethical Brain, 2005, etc.) knows his stuff-and a lot of other people's stuff too. The elegant popularizer trots out study after study in brain science, emphasizing evolutionary and developmental psychology as well as his own research on split-brain patients and others with neurological lesions. No surprise, then, to find him weighing human traits for their adaptive value in terms of safety, survival and reproduction, especially qualities that promote socializing and cooperation. Indeed, he sometimes argues too much for an adaptive value for well nigh every human feature he discusses. Gazzaniga describes how lesions reveal the brain's organization into myriad modules specialized for, say, recognizing faces (located in the right hemisphere). He argues for a left hemisphere "interpreter" who's in charge-making sense of all the inputs, but ready to make up stories if need be. This seems to put him in the camp of dualism, which supposes there is something else behind the physical substance of brain tissue that accounts for the mind; though the idea's been around since Descartes, it remains debatable. The author celebrates the unique richness of the human neocortex, more complex than in any other animal. By inference, the cortex and its extensive connectivity account for art, music, analytical thinking (and thus science), self-awareness, imagination and our ability to pretend and to evoke the past and future. Gazzaniga also declares that humans are unique in their ability to project the mental states of others:to understand that behind their behavior are minds like ours that have desires and beliefs. To his credit, he discusses controversies and conflicting studies in all these areas, as well as in the origin of language, consciousness, morality and religion. Credit him too with a wonderful final section on current research on robotics and gene manipulation. A savvy, witty guide to neuroscience today.

Product Details

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Table of Contents

Read an Excerpt

Human
The Science Behind What Makes Us Unique

Prologue

I always smile when I hear Garrison Keillor say, "Be well, do good work, and keep in touch." It is such a simple sentiment, yet so full of human complexity. Other apes don't have that sentiment. Think about it. Our species does like to wish people well, not harm. No one ever says, "Have a bad day" or "Do bad work," and keeping in touch is what the cell-phone industry has discovered all of us do, even when there is nothing going on.

There in one sentence Keillor captures humanness. A familiar cartoon with various captions makes its way around evolutionary biologists' circles. It shows an ape at one end of a line and then several intermediate early humans culminating in a tall human standing erect at the other end. We now know that the line isn't so direct, but the metaphor still works. We did evolve, and we are what we are through the forces of natural selection. And yet I would like to amend that cartoon. I see the human turning around with a knife in his hand and cutting his imaginary tether to the earlier versions, becoming liberated to do things no other animal comes close to doing.

We humans are special. All of us solve problems effortlessly and routinely. When we approach a screen door with our arms full of bags of groceries, we instantly know how to stick out our pinky and hook it around the door handle to open it. The human mind is so generative and so given to animation that we do things such as map agency (that is, we project intent) onto almost anything——our pets, our old shoes, our cars, our world, our gods. It is as if we don't want to be alone up here atthe top of the cognitive chain as the smartest things on earth. We want to see our dogs charm us and appeal to our emotions; we imagine that they too can have pity, love, hate, and all the rest. We are a big deal and we are a little scared about it.

Thousands of scientists and philosophers over hundreds of years have either recognized this uniqueness of ours or have denied it and looked for the antecedents of everything human in other animals. In recent years, clever scientists have found antecedents to all kinds of things that we had assumed were purely human constructions. We used to think that only humans had the ability to reflect on their own thoughts, which is called metacognition. Well, think again. Two psychologists at the University of Georgia have shown that rats also have this ability. It turns out that rats know what they don't know. Does that mean we should do away with our rat traps? I don't think so.

Everywhere I look I see tidbits of differences, and one can always say a particular tidbit can be found in others aspects of biological life. Ralph Greenspan, a very talented neuroscientist and geneticist at the Neuroscience Institute in La Jolla, California, studies, of all things, sleep in the fruit fly.

Someone had asked him at lunch one day, "Do flies sleep?" He quipped, "I don't know and I don't care." But then he got to thinking about it and realized that maybe he could learn something about the mysterious process of sleep, which has eluded understanding. The short version of this story is that flies do sleep, just as we do. More important, flies express the same genes during sleeping and waking hours that we do. Indeed, Greenspan's current research suggests that even protozoans sleep. Good grief!

The point is that most human activity can be related to antecedents in other animals. But to be swept away by such a fact is to miss the point of human experience. In the following chapters, we will comb through data about our brains, our minds, our social world, our feelings, our artistic endeavors, our capacity to confer agency, our consciousness, and our growing knowledge that our brain parts can be replaced with silicon parts. From this jaunt, one clear fact emerges. Although we are made up of the same chemicals, with the same physiological reactions, we are very different from other animals. Just as gases can become liquids, which can become solids, phase shifts occur in evolution, shifts so large in their implications that it becomes almost impossible to think of them as having the same components. A foggy mist is made up of the same stuff as an iceberg. In a complex relationship with the environment, very similar substances with the same chemical structure can become quite different in their reality and form.

Indeed, I have decided that something like a phase shift has occurred in becoming human. There simply is no one thing that will ever account for our spectacular abilities, our aspirations, and our capacity to travel mentally in time to the almost infinite world beyond our present existence. Even though we have all of these connections with the biologic world from which we came, and we have in some instances similar mental structures, we are hugely different. While most of our genes and brain architecture are held in common with animals, there are always differences to be found. And while we can use lathes to mill fine jewelry, and chimpanzees can use stones to crack open nuts, the differences are light-years apart. And while the family dog may appear empathetic, no pet understands the difference between sorrow and pity.

A phase shift occurred, and it occurred as the consequence of many things changing in our brains and minds. This book is the story of our uniqueness and how we got here. Personally, I love our species, and always have. I have never found it necessary to lessen our success and domination of this universe. So let us start the journey of understanding why humans are special, and let's have some fun doing it.