What a Fish Knows: The Inner Lives of Our Underwater Cousins by Jonathan Balcombe (review)

You shouldn't talk about "fish." Bony fishes are at least as distinct from cartilaginous fishes as birds are from mammals. A tuna is closer to a human than it is to a shark. Yet we insistently do speak of fish. It is a repercussive mistake, Balcombe argues, in this fascinating and important book. We paint our pictures of the natural world with a crudely broad brush. It suits us to do so. It is easier to justify our nonbiological but flattering self-image as the apex of creation (with a consequent license to abuse and exploit) if we see nonhuman animals in huge, monolithic categories, rather than as massively varied and individually charismatic. It is easier to maintain that convenient divide of "them and us."

Fishes (Balcombe's preferred word) have been systematically denigrated. It doesn't help that they don't have eyelids, particularly mobile faces, or the ability to vocalize in a way audible to us, which allows us to say (if we're biologically illiterate) that they don't have emotions; that they don't feel pain; that they have no sense of self—no sense of the value of their own lives. Yet we know that tramadol reduces the sensitivity of fishes to electric shocks in a dose-dependent way and that human anxiolytics reduce the signs of anxiety in fishes. You can teach Koi carp to distinguish between the Bach oboe concertos and John Lee Hooker, and once they've learned to do so, they can generalize the distinction when introduced to other classical composers and blues artists. Many of the capacities possessed by fishes hint strongly at consciousness: learning, memory, the recognition of individuals, play, tool use, cooperation, and the keeping of accounts.

Here is the unflattering truth: consciousness probably evolved in fishes; we inherited it from them. If the human time on earth is one second, fishes have been around for more than four minutes. We should respect our elders.

No fishes have good deaths. We probably kill more than 30 trillion of them a year. We crush them, disembowel them, decompress them until their entrails are forced through their mouths, and asphyxiate them. It is psychotic behavior. And yet the image of a boy with a fishing rod is an icon of the good, innocent life.

Balcombe's superb account calls us urgently to reevaluate our attitude—not just to fishes, but to all things that are different from ourselves.