I am busy making a separate page on my blog to discuss how my work with the signing apes has been cited and quoted in publications by others. The first article of that page I discuss here in this post. It’s: Todd M. Preuss. (2006). Who’s afraid of Homo sapiens? Journal of Biomedical Discovery and Collaboration, 1, 17. Click here for the article itself. Dr. Todd Preuss is associate research professor at the Division of Neuroscience of Emory University’s Yerkes National Primate Research Center in Atlanta. He carries out fundamental research on the structure and evolution of the primate cerebral cortex. He compares the anatomy of cortical layers and areas in humans, chimpanzees and monkeys. In this article Preuss discusses the recent attempts to stop doing experiments with great apes. He argues that chimpanzees and other great apes should still be available for (non-invasive) research, in order to obtain a better understanding of the species-specific features of the human brain.
My article in the Journal of Comparative Psychology gets cited when he talks about how comparative research with humans and apes has changed through the years: “Popular culture today takes it as given that apes share with humans the capacity for language. Students of language, however, have for the most part drawn the opposite lesson from the ape-language project, concluding that apes demonstrate little productive language capacity, even after intensive training, and that language is a human specialization (e.g., [5-12]).” The references cited here include my article, together with work by Dereck Bickerton, Steven Pinker, Marc Seidenberg and Laura Petitto, Terry Deacon, Philip Lieberman, Michael Tomasello, and Joel Wallman’s 1992 book Aping language. It is true that my research with the signing chimpanzees has shown that the apes’ signing behaviour cannot be considered linguistic and I claim that language is species-specific for humans only. However, and this is what I feared when I obtained my results, my conclusion about the absence of language in nonhuman apes should not lead to the idea that it is therefore morally justified to treat nonhuman apes different from humans, simply because of this difference. In the Epilogue of my dissertation I discuss the moral implications of my findings. Instead of interpreting my data as a justification for using great apes in research, I argue that we should still treat all sentient animals equally. This is because only sentience or phenomenal consciousness is the necessary condition for inherent value and therefore for equal treatment, and not a more complex cognitive capacity such as language (see also my 1997 chapter in Animal consciousness and animal ethics). I have to admit that Preuss does not use my work here to advocate a moral difference in treatment between humans and nonhumans, and only refers to it to show the changes in thought of comparative researchers. However, it is interesting that my work is cited in an article that argues for the continuing use of great apes in biomedical research.
Preuss makes claims in the article that are morally objectionable. He says that we need more comparative studies of the brain, for example by using neuroimagining techniques. Claiming that this is an ethically acceptable way of studying the brain in humans, he says that we could use those new techniques in nonhuman apes as well. Though I’m unfamiliar with these techniques, such research with apes will always include keeping the apes in captivity, and probably restraining them in some form or other. This is not “ethically acceptable”, because it robs the ape subjects of their individual freedom. Another technique Preuss suggests is to do histological studies using brain tissue obtained postmortem. Again, moral questions can be posed here. With humans, we have the possibility of informed consent: the humans whose brains will be analyzed will have given consent before their death to use their brains for research. Furthermore, where will the ape brains come from? I have yet to see a chimpanzee carrying a donor card that specifies that his or her body can be used for science after death. I presume that Preuss is suggesting we carry out such brain research with apes that have died in biomedical labs or zoos. Which confronts us then again with the captivity issue. If keeping apes in captivity is morally objectionable, then so is using their brains after death. Comparative genomics is another form of research that Preuss would like to see done, and this could be done by “employ[ing] any of the growing array of non-invasive, non-terminal techniques (biochemical, proteomic, imaging, behavioral) we have for comparing humans to other animals.” Again, the non-invasiveness and non-terminalness of such techniques leaves aside the moral problem of captivity.
Ending his article with the section Will there be chimpanzees to study? Preuss would like to see the moratorium on breeding captive chimpanzees lifted (imposed in the USA by the National Institutes of Health in 1997), so that science can continue the comparative studies that would be of great value in understanding the human brain. Especially with chimpanzees facing extinction, breeding for science should be allowed. From an egalitarian point of view, Preuss’s position here means that chimpanzees will be subject to further captivity, forced breeding and the intrusion of their freedom in comparative research. Rejecting such research because of these moral reasons means that we cannot improve our knowledge of the human brain in that way. However, with humans as scientific subjects we accept certain moral constraints, which also means that we can’t increase our knowledge in the same way as when we would allow ethically unacceptable scientific practices with humans (and I know of no scientists that advocate such practices because it would further our knowledge). Considering nonhuman animals as our moral equals means we similarly accept certain limits on the increase of our knowledge and our possibilities of fighting diseases.