Behind What Makes Us Unique.The book reveals a vast knowledge and deep understanding of the human brain, yet it is written in an affable and engaging style that lets Gazzaniga's loveable 'wise guy' persona shine through.In teeing up the deeply philosophical issue that the book will examine-whether there is a continuity or discontinuity between us and the rest of the animal kingdom-Gazzaniga eschews lofty allusions and asks very plainly, "What is the deal with humans?"Although Gazzaniga's approach may be lighthearted, he contributes substantially to a debate that has a venerable history.Charles Darwin reasoned that the difference in mind between man and the higher animals, great as it is, certainly is one of degree and not of kind.For most of the twentieth century, research emphasized the similarities between the mind, brain and biology of human and nonhuman animals, demonstrating that we are not unique in our use of language, tools, cultures, syntax or even teachers.Although granting that most human activity can be related to antecedents in other animals, Gazzaniga reminds us that a foggy mist is made up of "the same stuff" as an iceberg."Just as gases can become liquids, which can become solids," he writes, "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."Gazzaniga clearly sides with those who see something like a phase shift having occurred on our path to becoming human, yet he grants, "There simply is no one thing that will ever account for our spectacular abilities."He sees "our aspirations, and our capacity to travel mentally in time to the almost infinite world beyond our present existence" as a result, in part, of the modular nature of our brains, combined with a degree of connectivity that is exponentially greater than that found in any other species.And yet specific benchmarks do emerge: the anatomy of the human throat that allows for speech, our ability to inhibit our emotional Are humans unique?