Question: About a month ago, we discussed behaviorism in class. I remember you stating that behaviorists believe all animals are equal, but that was all that stuck in my mind. Was there more to this discussion that I am missing?
Answer: Yes. And here's the important thing: Keep in mind that behaviorism tried to make psychology a science. The goals of science are to predict and control. To achieve these goals science tries to discover general laws that can be applied to many different situations. For example Newton's theory of universal gravitation explains both why apples fall and why planets orbit the sun with only a single principle (objects attract with a force proportional to their masses and inversely proportional to the square of the distance between them). The more things a theory explains the more parsimonious it is.
Psychology under the behaviorist regime focused on behavior as its subject matter. As a science it tried to develop parsimonious explanations. Since behavior was its domain, it tried to explain behavior — all behavior. It would not be parsimonious to have a different set of laws for each animal's behavior. Psychology wanted one general set of laws that would explain all animals' behavior. To do this it was necessary to assume that all animals were basically the same — i.e, they all learned in the same way. This is why the psychologist B.F. Skinner in looking at a graph of the learning curves of several animals made the comment, "Rat, pigeon, monkey, human — which is which? They're all the same." If every "citizen" is seen as equal to every other "citizen", then that's a democracy. This was a central tenet of behaviorism that all learning is acquired in the same way in all animals. Later this was challenged successfully by Garcia and Seligman who showed that some animals were "biologically predisposed" to learn certain tasks better and some stimuli could not paired with some responses.
Nevertheless this democracy of behaviorism (which was in part fostered by evolution) allowed findings for one animal to be generalized to another. If we learn just like rats, we can take the priniciples that we discovered about rat learning and apply them to humans. That's the power of science. Most (not all) of the learning principles that we routinely apply to humans have come from animal studies. (Animals are cheaper and more convenient to study and when you're done with them, you simply "sacrifice" them.).
This was an excellent question and although it could have been asked in class, this is fine too. I'll just post it as a link.