The Gap: The Science of What Separates Us from Other Animalsby Thomas SuddendorfBasic Books, 2013The subject of Thomas Suddendorf's new book The Gap is "the chasm that currently separates human and animal minds," and the book itself is merrily undeterred by the fact that such a gap is either trivial or nonexistent. Suddendorf may open his discussion with ecumenical sops like "Humans tend to think of themselves as better than, or at least separate from, all other species on this planet ... But every species is unique, and in that sense humans are no different," but he neither believes such things nor expects his readers to believe them. Other species might be unique, but only one is superior. For all its extensive 21st century scientific trappings, The Gap is a triumphalist, almost Calvinist, celebration of human uniqueness that could have come have come virtually unchanged from any Victorian undergraduate zoology class.Suddendorf centers his contention of mankind's superiority on a handful of cognitive strengths of the human brain: the ability to imagine many hypothetical results of any decision, the ability to mentally 'time travel' along the whole spectrum of a choice's lifespan, the ability, almost the hunger, to exchange copious amounts of data verbally, the facility of contemplating the self, etc. The bulk of his book is dedicated to isolating these few strengths, equating them with being 'advanced,' and detailing how good-natured human scientists such as himself continue to test the lower orders of the animal kingdom in order to determine just why they fall so short of achieving human greatness. That the tests are conducted entirely on imprisoned, bored, captivity-deranged individuals only rarely and hazily seems to occur to Suddendorf, which yields quite a few passages that are unintentionally and grimly funny, as in his account of dealing with some dolphins at SeaWorld:

At first, we rewarded them for touching with their nose one of two boards that displayed a symbol they were shown beforehand on the other side of a pontoon. We then wanted them to match items that were perceptually different but represented an analog [sic] relationship. Alas, the dolphins were poor at this task. When they got it wrong, instead of examining the problem, they would try to hit the board harder or do a flip first or some other fancy trick. As we have seen, negative results are difficult to interpret. One possible explanation for our findings is simply that their interactions with humans typically involve fish rewards for acrobatics rather than for correct choices.

"One possibly explanation" - it's rich. It's like idly speculating that perhaps an environment of coercion, solitary confinement, and sodomizing is "one possible explanation" for prison convict anger. And in almost every parallel example, from elephants showing abundant signs of self-awareness to animals from ants to songbirds to orangutans using projection and tool-making to get food from their jailors, there's a parallel hemi-dismissal on hand. When writing, for instance, about the enormously well-attested cognitive abilities of crows and ravens, Suddendorf cautions us:

Yet there remains some lingering skepticism about these cases of animal problem solving. As we have seen repeatedly, behavior that looks smart need not necessarily be the result of intelligent thought.

This sort of thing is common enough to be a bit depressing. Even the most purblind of scientific analysis in the last twenty years has made it clear that the peculiar mental abilities Suddendorf enumerates are important but tiny quirks rather than signposts around true yawning gaps. Yes, the human brain has evolved better conceptualizing capabilities than most other animals have (though hardly all, as Suddendorf continually implies; sea lions saturate their lungs with oxygen and then dive straight down into complete darkness in search of moving food - to put it mildly, they're well capable of extrapolating hypothetical future outcomes of their actions. But then, refuting examples are too numerous to mention), but those abilities are just a few of the things brains can develop to do. It's the worst kind of species game-rigging to first develop those abilities and then construct "intelligence" tests based solely on them. And even with the game-rigging, humans come out poorly; it's extremely unlikely that Suddendorf could 'score' so well at thinking like a dolphin as those SeaWorld dolphins did at thinking like a human.The most refreshing thing about this book is Suddendorf's moderate willingness to confront where "the gap" comes from in the first place - not the lack of "advanced" thinking, but the lack of thinkers. He reminds us that this was not always the case:

Great apes have not always been our closest living relatives. Only two thousand generations ago humans still shared this planet with several upright-walking, fire-controlling, tool-manufacturing cousins, including big Neanderthals ( Homo neanderthalensis) and small "Hobbits" ( Homo floresiensis). With its various bipeds it was a world reminiscent of Tolkien's Middle Earth. Our ancestors forty thousand years ago would have had much less reason to believe they were far removed from the rest of the Earth's creatures. We were but one of a group of similar species.

And alongside the customary palaver about climate change and interbreeding, he's willing to entertain - faintly, diffidently, but we take what victories we can - another possible explanation for the fact that all those other species of human aren't here anymore:

One way or another, its seems likely that our forebears played important roles in the disappearance of at least some of our closest relatives. The reason the current gap between animal and human minds seems so large and so baffling, then, may be because we have destroyed the missing links.

And of course that particular gap is widening a little more every day, which occasions the bracingly sorrowful concluding portion of Suddendorf's book:

There are, of course humans who are desperately trying to stop the extinction of apes, and I encourage you to join them, but the current projections are bleak. In a couple of generations, our descendants might wonder at just how different they are from their closest remaining animal relatives: the monkeys. Apes my join Neanderthals and Paranthropus as half-forgotten creatures of the past. So our descendants may be even more baffled by their own apparent uniqueness (and possibly be distracted by questions about the importance of the fact that monkeys typically have tails whereas humans do not). Let's make sure they are more enlightened about the nature and origin of the gap.

The nature of the gap is made slightly less rather than slightly more clear in the pages of The Gap, and the origin belies all this talk of remarkable human cognitive abilities, which are shared to a very large, in whole or in part, by a very large contingent of other species; the real gap isn't the human brain - it's the vicious, genocidal, murdering mind inside that brain. Only the so-called 'higher' primates have that, and none has it so adamantly as Homo sapiens. There's a gap for you.