How would we go about testing this? If we one day discover a non-human animal which does use concepts, what implication(s), if any, would this have with regard to animal rights?
I thought this was already asked somewhere, but if so I can't find it. All three questions are important, but they are related enough I thought I should keep them together.
For the second question, I definitely think it is going to involve looking at animal use of language. Rand has said that "without concepts, there can be no language". One might look to this and close the case. There are many species of non-human animals which use "language". But I'm not convinced that this isn't an equivocation. On Wikipedia there is a comment that "animal language" should not be confused with "animal communication", and the only examples I can think of probably fit under "animal communication" and not "animal language".
The second question is probably too large of a topic to answer in detail. It's probably even too large of a topic for me as a non-expert to expect to understand. However, I'll ask, and we'll see what we get.
In March 2012, I discussed animal cognition issues in some detail on this website in answer to the question, "Do Objectivists take the position that animals do not have free will?" (Link). There were some specific references on animal cognition cited in that thread, which I checked out and discussed. I will also be interested to know if the same criticisms also apply to the references cited in this thread so far. (I have not had time so far to try to check the current references myself. It would help if the commenter who cited those references could also provide weblinks if available.)
Here are some specific issues to consider:
(a) "The function of your stomach, lungs or heart is automatic; the function of your mind is not. In any hour and issue of your life, you are free to think or to evade that effort. But you are not free to escape from your nature, from the fact that reason is your means of survival—so that for you, who are a human being, the question 'to be or not to be' is the question 'to think or not to think.'" (Quoted from Galt's Speech in Atlas Shrugged.)
(b) Man can form abstractions from lower-level abstractions, i.e., integrate previously formed concepts into wider concepts having a higher level of abstraction (greater distance from direct perception) than the previous concepts.
(c) Man makes tools of all kinds, with increasing levels of complexity and power; man also makes fire and uses it for cooking, warmth and other purposes; man man also creates artistic artifacts of all kinds, including paintings on the walls of caves, on pottery (which is itself man-made) and elsewhere. Man creates musical sounds and entire compositions that go far beyond mere "chirping" of birds, crickets, and the like, or calls by wolves, elephants, whales, and so on. Man uses clothing for warmth and other protection from nature; he uses vehicles for transportation, including vehicles with wheels, vehicles that fly, and vehicles that swim.
(d) Man knows math and science, and how to employ such knowledge in technology and industry. He constructs buildings, including skyscrapers, not just tunnels in the ground or piles of mud or sticks.
(e) Man can learn the concept of "rights"; he can respect the rights of others, and he needs recognition and protection of his rights in order to live. Rights have no meaning or applicability in the lives of other animals.
Considering the vast scale of man's intellectual capacity compared to any other animal, it is almost irrelevant to be particularly excited about any concept-like similarities to animal cognition -- or to suggest that the concept of rights could be applicable to (or understood by) any other animal. (Newborn human infants cannot understand the concept of rights, either, in the beginning, but they still need at least the protection of their right to life, even if they are far too young to exercise and benefit from other rights such as the right to liberty, property, freedom of speech and association, the right to vote, to assemble peacefully and petition the government for redress of grievances, etc. The issue of why newborn humans have a right to life while other animals and unborn fetuses do not is a key differentiator in understanding rights in general.)
Update: Perception and Concepts
The Google suggestion by orb8 in the comments has proven to be a good one, allowing me to find and peruse orb8's references on animal cognition fairly easily and quickly. (One reference apparently requires payment of a fee to get the complete paper, but I was able to read the abstract without having to buy anything.) I also checked the reference on Orcas. What I found in all these references can be summed up as follows:
(a) The feats that many animals are capable of performing, with or without extensive training by man, are often quite impressive by man's standards of perceptual functioning. Man certainly would not be able to do all those tasks by trying to function entirely on the perceptual level, without benefit of concepts (possibly aided by technology based on man's concepts). It may be easy to assume, therefore, that the animals must be using concepts, as man does. Yet it is also striking that none of these animal observations have ever succeeded (as far as I know) in simply asking an animal what it "thinks" and having it explain itself to humans. One simply can't do that with animals. One can only construct sophisticated experiments involving a lot of often ingenious stimulus-response-reward conditioning followed by some kind of test, or sometimes just observing what animals do naturally in the wild (as with the Orcas). Observers all too often seem to have a very minimal view of both perception and concepts, treating perception as a simple, mirror-like process, and likewise treating conceptual functioning as rudimentary and limited, too, in its most basic, concrete-centered forms.
(b) Objectivism, however, points out that there is vastly more to conceptual functioning than animal cognition observers may be assuming. Historically, of course, the whole field of philosophy has offered little insight on the nature of concepts in man. Ayn Rand's work on human concepts is still very new historically and poorly understood. Observers such as obr8 can readily come along and pick out specific statements, apply conventional assumptions about the nature of concepts, and conclude that Objectivist claims about the limitations of animal cognition are mistaken. It is clear to me, however, from the extensive Objectivist materials available today on the nature of concepts in man, that the critics of Objectivism are wrong. They have not understood the Objectivist view of human concepts at all. To animal cognition observers and human cognition observers alike, therefore, I would offer the following basic principle:
Never underestimate the power of the perceptual level of cognition in animals that are constituted to live on that level in a correspondingly conducive habitat. The perceptual level is more effective for those animals than man may have hitherto assumed. Both the recent experiments and the vast array of past observations of animals historically have amply demonstrated this. Those observations do not demonstrate, however, that animals are using human concepts, or functioning on a conceptual level at all, as that form of cognition is understood by man.
There is extensive material in the literature of Objectivism on concept-formation and conceptual functioning in man, especially Ayn Rand's book, Introduction to Objectivist Epistemology (ITOE), Expanded Second Edition. There is also a whole chaper on "Concept Formation" in OPAR. For an overview, one can start with the following entries in The Ayn Rand Lexicon:
The topic of "Crow-Epistemology" redirects the reader to "Unit-Economy," and the connection to crows is explained in ITOE. Anyone seriously seeking to challenge Objectivism on the nature of concepts will need to become thoroughly familiar with all of this material, and will need to show that he understands it. One cannot take small fragments of it, apply conventional definitions of terms (which may be woefully inadequate and confused), and decide that Objectivism is wrong.
At a high level, my original answer indicates some of the questions that should be asked about animal cognition when comparing it to human conceptual cognition. Within the category of Objectivist identifications, one should also ask: where or how do animals demonstrate that they can perform measurement omission and isolate specific characteristics involved in similarity, apart from the specific measurements of those characteristics? Where or how do animals demonstrate that they can assign a visual-auditory symbol of some kind to a mental integration and then treat it as a concrete existent in further conceptualization? Where or how do animals demonstrate that they explicitly regard concretes as units of a type or kind?
Regarding this last, animals surely do perceive entities of different kinds and react differently depending on the kind of entity they are perceiving. The key issue is whether that really proves that they have reached the stage of treating existents as units, or are merely perceiving the existents as they are and reacting automatically to what they can perceive. Since animals other than man have not, so far, been observed assigning visual-auditory symbols to groupings of concretes, man can quite logically conclude that animals are doing what they do entirely perceptually, without benefit of human-like concepts.
Regarding visual-auditory symbols, there have been impressive experiments in trying to teach sign language to chimps and porpoises, but it still remains unclear that the animals actually understand the signs as symbols for types or kinds of concretes. It seems more likely from the evidence that the animals are merely associating the symbol perceptually with a line of concretes which they have observed in the past and which are similar to each other, and then searching for perceptually similar new concretes in their habitat when instructed to do so by human trainers.
A casual observer might assume that a concept is nothing more than an arbitrary grouping of concretes, with some kind of name or identifying symbol assigned to the group. But that is a grossly deficient view of how man forms and uses concepts. For example, does such a group include only the particular members that were used to form the group? What about new concretes that man observes later? Should they be included in the group, too, if they are sufficiently similar to the existing members? What does "sufficiently similar" mean? Why is similarity needed at all? What kind of similarity should be adopted as one's criterion for group inclusion or exclusion, and why? And so on. Objectivism deals with all these issues and many more.
Nonhuman animals, in contrast, merely perceive. This includes remembering and perceptually associating according to perceived similarity. There is no demonstrable process of measurement omission and abstraction in what they do. Animals (other than man) do not, so far as we know from all available evidence, go beyond their perceptions of similarities to isolate essential distinguishing characteristics and integrate concretes into abstract mental groupings which can then be used like concretes in still more abstract mental groupings. Like man, animals can perceive similarities and perceptually associate remembered concretes acccording to perceived similarities. But they can't go any further than that, as man does with measurement omission and abstraction.
One does not need concepts in order to perceive similarities between concretes; on the contrary, the similarities have to be perceived first, before man can form and apply concepts. Likewise, one does not need concepts in order to remember a number of concretes that are all very similar to each other, and then recognize that a new concrete is also very similar to the others. All of that can be done entirely perceptually, without concepts, though not with the same degree of precision and subtlety that man's concepts enable in man. This aspect of perception may be very unfamiliar to man because man has such enormous capacity to shift into conceptual cognition so easily. Again, understanding the full scope of how man forms and uses concepts requires careful study of the whole range of Objectivist materials that I noted above.
Man can also approximate the perceptual (non-conceptual) mode of cognition simply by going out of focus:
Man can focus his mind to a full, active, purposefully directed awareness of reality—or he can unfocus it and let himself drift in a semiconscious daze, merely reacting to any chance stimulus of the immediate moment, at the mercy of his undirected sensory-perceptual mechanism and of any random, associational connections it might happen to make.
(From VOS, excerpted in "Free Will" in The Ayn Rand Lexicon.)
Animals do that automatically, and it works well for them in correspondingly conducive habitats (they have no capacity to do otherwise). But it doesn't work well at all for man. Man needs concepts.
Even if we allow that some animals other than humans use some concepts, there is no question that the extent to which humans use concepts far outstrips what any non-human animal achieves.
In the answer written by Ideas for Life, his lettered examples are just some of the many ways in which man makes extensive use of concepts.
This extent is so great, that these ways in which man uses concepts, taken together, emerge as a new way of survival which only Man has. Concepts are, for man, essential to how he lives.
Animals do not use concepts to survive. As far as I know, any animals which might be considered to use concepts do so to entertain researchers who wish to obliterate the essential differentiation between humans and other species.
So, it's not whether animals can use concepts (I'm doubting any do) which determines whether they have rights. It's whether they can and do use them to survive, and whether they have the capacity to understand and respect the rights of humans.
The day I see a non-human animal involved in an argument, presenting propositions and reasons, rather than a fight, is the day I'll consider that they might have rights.