The interrelated topics of animal research and animal rights bring out powerful emotions in many people.  There's no scientific consensus converging on an answer. What bothers me is that I'm not sure humanlike intelligence and self-awareness should be the only thing considered when deciding whether an animal should be subject to research that causes it harm.

My own cat Higgs may not be particularly intelligent, despite having his own Google + account and twitter handle Darwins_Hellcat. In his real life he's sweet, shy and so easily terrified that he hides in the closet when anyone sneezes. The thought of him caged in a lab or used in a biomedical experiment is horrifying.

I have the same revulsion to dogs being used in invasive experiments. I confided this to a biologist who responded to the column and here's what he wrote back:

"Cats and dogs are so attuned to humans that it strikes me as unconscionable to betray that trust in any way.  Maybe that kind of work has to be done (though I'm not sure that's true), but I couldn't do it."

Other readers said I "hit a nerve" by writing about people who wanted to curtail chimpanzee research that might improve human health:

"A major driving force for biological scientists is to understand better biological processes, from molecular to behavioral.  I would guess that the majority of us also hope that this information helps to alleviate diseases, with the major emphasis on those afflicting our own species.  The test subjects or materials used are determined by which will most likely provide the answers to the questions we pose, although cost is also limiting factor.  They range from animals and plants of the different Phyla to in vitro studies using any number of organisms. The pig is often used in studies of digestion as their digestive system is closely related to that of humans, the fruit fly for many genetic studies as it reproduces so rapidly, primates for behavioral studies as their brains more closely resemble ours, etc. The genus and species used number in the thousands, and include Homo sapiens. Rodents are far and away the most common species used as there is so much already known about them, they have been genetically inbred for so long that they are virtually identical to each other(a great advantage in reducing biological variability), and they are relatively inexpensive.  From the scientific standpoint, humans are probably the worse species to use because, beside the ethical issues, they are extremely variable in their responses and are the most expensive to study.  Finding a good animal model for a disease is the Holy Grail for biological investigators, as it often leads to a rational treatment of the human disease.

Carried to its logical extreme, critics of the use of non-human primates to study behavior, the main subject of your article, should also object to the use of any living thing, as we all have genes in common. This would essentially halt in its tracks all advances in the biological sciences and progress in alleviating human diseases.  

There are already adequate controls, rules and regulations, both governmental and institutional, to prevent mistreatment of animal subjects.  More importantly, no normal scientist mistreats their experimental subjects, not only because they are fundamentally ethical themselves but also because their proper treatment provides the most reliable scientific results."

And this from a reader who runs an animal law group on Yahoo.com:

"What's happening here is that a few humans are deciding that it's better for
all humans to suffer more so that a few chimps can (arguably) suffer less on
their way to extinction.   Perhaps this is really a majority view now, but I
wish we could actually discuss it rather than simply nod approvingly as a
government that represents only a few of us, imposes it."

But others were more critical of animal research, regarded some of it as "torture". Other email responses, such as this one from a physician, express philosophical and ethical concerns:

"I often wonder who gives us the arrogance to consider ourselves the owners of the Earth.

Last Fall I got fascinated by a video of some chimps, kidnapped as babies from the African jungles, taken to an Austrian facility for experimentation, kept there for 30 years, and eventually released after the drug company had gone bankrupt.

The video captured the moment they went out in the open for the first time, smiling and hugging each other, and actually looking very human in the process. It reminded me of footage from Auschwitz, and in fact I ended up putting it in a talk I give on human evil, the Camps, and why Docs were perpetrators instead of rescuers."