If you’ve heard the name Edward Thorndike, you are probably aware of the importance this psychologist had on early behavioral science. He was the one that coined the term law of effect, which is a theoretical precursor to the process of reinforcement. Thorndike was interested in psychology as an observable natural science, which at the time flew in the face of introspective methods. His work inspired many of the ideas and theories of B.F Skinner, and behaviorism as a whole, but what you might not know is that his big break came from what he learned from…cats.
People who are familiar with Thorndike’s law of effect are aware that his theory underwent several revisions, and his research came into criticism; but few would dispute that his dissertation on the associative processes of animals, and the puzzle box experiment raised the right questions that would lead to many of the processes within operant conditioning that we see used today. Thorndike owes much of that to the cats he worked with during the animal research. Thorndike was interested in animal learning. Could they learn? Were all their behaviors governed solely by reflex? If they could learn, what could they learn? Could they learn by observing others? To us modern readers, who are familiar generally with animal intelligence levels, this might seem like a no brainer, but in the late 19th century when Thorndike was doing his work a sizable amount of academics still held on to the old Cartesean view of animals as unconscious automatons. These cats, and Thorndike, would call that into question. They would demonstrate that they could not only learn, but overcome an obstacle that could not possibly be a part of their reflex system- a puzzle box. Cats solving puzzles?! Thorndike must be mad! (I’m not entirely sure his critics would have been that dramatic, but skepticism was definitely there.).
His experiment was simple. Place hungry cats within a box that required a simple action to open, in order to access food outside of the box. The puzzle box itself had a door which was shut by weighted string, and that string was attached to a lever or switch; by operating these, the door would open. There were other future experiments involving buttons which worked in a similar fashion, but the single response (which was not reflexive) was consistent. At first the cats wandered around the cage meowing, and circling, until they incidentally stepped or pushed on a lever, opened the door, and gained access to the food. This was not learning. This was incidentally triggering the device. BUT… when placed within the cage again, these cats were able to reduce their time wandering and meowing before they found the trigger and let themselves out. Thorndike tracked these times, noticing not only that these cats were able to find their way out faster each time, but also the rate at which this learning took place. Thorndike constructed a learning curve. The cats struggled at first, but got faster with each new trial until their rates of responding became efficient enough to level off. Thorndike believed that to even perform this type of learning required some intelligence intrinsic to the cats. Obviously some kind of intelligence that did not rely on language or introspection.
“From the lowest animals of which we can affirm intelligence up to man this type of intellect is found.”- Edward Thorndike
“Meow.”- Edward Thorndike’s Cat
Thorndike’s initial hypotheses were not always correct or confirmed however. Learning through observation, for example, was something he could not capture with these puzzle box trials. During the initial trials, he was not able to observe a difference in the rates of cats’ responding learned through their own trial and error, and cats who observed others escaping by pressing the lever/switch. (Later studies with other animal subjects would, of course, demonstrate animal learning through observation could in fact occur with certain animals). He also believed there might be some level of insight from the cats which helped them learn these tasks, but that too was not confirmed by his initial experiment- cats seemed to be more gradual learners from experience. This type of learning, again, appeared not to rely on language or introspective thought. Thorndike noticed that when he first put cats inside the puzzle box, their behavior seemed “erratic” or “chaotic”, but after successive trials the became more focused on finding the trigger to opening the door and engaged in fewer responses which did not align with the task. The cats were no longer circling and meowing; they were approximating responses that were previously successful and allowed them access to food. Thorndike concluded from this that this was responding based on the law of effect; that it happened due to past consequences. This would later be called by behaviorists as reinforcement, and documentation of the three term contingency.
“There is no reasoning, no process of inference or comparison; there is no thinking about things, no putting two and two together; there are no ideas – the animal does not think of the box or of the food or of the act he is to perform.”- Edward Thorndike
“…”- Edward Thorndike’s Cat operating a puzzle box trigger.
That’s not all. Thorndike also theorized that cats could engage in discrimination of human vocalizations, and behave differently in situations after being spoken to. Thorndike noticed that when he approached cats behind wired netting before feeding, they would leap up on to the netting and meow.
(this author’s cat demonstrating exactly that)
To test this, he tested a loud proclamation in each condition:
“I MUST FEED THESE CATS!” (emphasis not present in original text)
Preceding conditions where he fed the cats, and
“I will not feed them.” (lack of textual enthusiasm probably accurate)
preceding conditions where he did not feed the cats.
He tracked these presentations and trials using frequency data collection, and in the conditions where he spoke “I must feed these cats”, and fed the cats, he found that cats would leap up more readily in the future, over the phrase where he did not feed them. This concept would later be referred to as responding to a discriminative stimulus. The cats would leap up and approach Thorndike (up to 60 times in the original research!) in the first condition, but also reduced leaping up when he voiced that he would not feed them. Thorndike was well aware that these cats were not spontaneously learning the English language, but they were discriminating between two very similar vocalized stimuli, and responding based on their previous experience and reinforcement. These ideas were not commonplace, or as well established as they are today. In many ways, these advances brought up unheard of avenues for the theory of learning in both animals and humans.
The theoretical implications of these experiments would shape later behavioral research into principles of operant conditioning well into not only the 20th century boom of behavioral thoughts and ideas, but even our time now in the 21st century.
Pretty impressive for cats, isn’t it?
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Picture Credits: http://www.pexels.com, Christian Sawyer (Photo)