A Review of “Do Fish Feel Pain?”

Abstract

Do fish feel pain? Perhaps the real question is: Do humans think that fish feel pain? The conclusions that individuals develop in answer to the second question seem to depend on the beliefs they have about fish and, perhaps, animals in general. Beliefs, in turn, may or may not involve solid evidence, but beliefs always involve assumptions. Assumptions are part of everyday life, including science. Many people assume that animals, especially vertebrate animals have some human characteristics. Assigning human characteristics to other animals in the absence of strong evidence is anthropomorphism. In this book, Victoria Braithwaite attempts to move beyond anthropomorphism on the question of whether or not fish feel pain. Does she succeed, or does her science include unsupported assumptions that influence the conclusions she develops? All science involves assumptions. The important thing is to recognize the assumptions and to be certain that the conditions required by the assumptions are met. We assume that animals used in our experiments are representative of a larger population and that experimental conditions are “normal.” When assumptions are not recognized, they can have major effects on results and subsequent conclusions. If assumptions are understood to be optional, the effects can completely negate the conclusions of a study. If the assumptions that we accept lead us to exclude alternative conclusions that are consistent with experimental results, but incompatible with our assumptions, the conclusions probably are biased. Victoria Braithwaite has made a valiant attempt to move the arguments about fish pain beyond beliefs and human perceptions about fish. The research described in her book was planned and executed with care. However, in my opinion, she has failed to provide a scientifically valid answer to her question, because she accepted invalid assumptions concerning pain, nociception, and associative/procedural learning (formerly called “conditioning”). I’ll return to these issues and some additional concerns that I have, but a summary of the book’s content is in order to give readers a better frame of reference. In Chapter 1, the author describes the aim of this book as an attempt to bring the science behind the arguments about pain and fish into the open so that informed discussion can take place. The first chapter, “The Problem,” does an acceptable job of establishing a broad foundation for such a discussion. Chapter 2, “What is Pain and Why Does it Hurt?” chapter begins with the statement that “pain is a personal experience. . .” This is absolutely correct, but it would be more accurate to state that it is a “personal, psychological experience”. Even with humans, with whom no one doubts the reality of pain, we only experience it when we are conscious and the appropriate parts of the brain are fully involved. The author goes on to ask the question “Are animals consciously aware of the pain?” Such a statement carries the assumption that there is pain and the pertinent question is only whether or not the animal is aware of it. Is this a legitimate question? Is it a testable question? Dr. Braithwaite carefully builds a framework for answering these questions in the affirmative, a result that appears to be exactly what she wanted. Chapter 3, “Bee Stings and Vinegar: The Evidence that Fish Feel Pain,” is devoted not only to descriptions of the studies that Braithwaite and her colleagues conducted but structural similarities between fish and humans that may be relative to the ability to experience pain are also discussed. Central to this discussion is the presence of nociceptive receptors (sensory structures) and neural pathways that are similar. In fact, these sensory receptors are referred to as “pain receptors,” thus implying that pain is an external force of some type. In Chapter 4, “Suffer the Little Fishes?” Dr. Braithwaite acknowledges the fact that pain is a psychological matter: “Feeling pain is an emotional experience.” She goes on to state that in order “To find out whether animals feel pain, we need to design experiments that let us glimpse inside their minds to test what the animals are mentally experiencing.. Later in this chapter, the work of Dr. James Rose, author of the most definitive review of fish neurobiology, is challenged because he concludes that fish lack the essential neural structures to experience pain as humans experience it. Differing definitions or assumptions