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If you have ever practised a type of problem until it became automatic, you have used the idea Edward Thorndike put into words more than a century ago. He studied how animals learn by doing, and then asked whether practising one skill makes the mind better at everything. His answers are still useful for anyone preparing for a big exam. This post explains his experiments, what he concluded, and how to turn both into study habits.
What were Thorndike's puzzle boxes?
Thorndike described his method in his 1898 monograph, Animal Intelligence: An Experimental Study of the Associative Processes in Animals, reprinted as a chapter of his 1911 book and available through York University's Classics in the History of Psychology. Hungry animals (kittens, dogs and chicks) were put into enclosures they could escape "by some simple act, such as pulling at a loop of cord, pressing a lever, or stepping on a platform". Food was left outside in sight. He recorded how long each animal took to get out on each trial, and repeated this until the animal escaped at once.
He notes that most of the experiments were done in the Psychological Laboratory of Columbia University in 1897–98, with some preliminary work at Harvard.
What did the cats actually do?
At first, a cat struggled, clawed and squeezed at everything. Sooner or later it hit the loop or button by chance and the door opened. Thorndike's description is vivid: "gradually all the other non-successful impulses will be stamped out and the particular impulse leading to the successful act will be stamped in by the resulting pleasure, until, after many trials, the cat will, when put in the box, immediately claw the button or loop in a definite way."
The important point is *gradually*. The escape times did not drop suddenly, as if the cat had a flash of insight. They fell over many trials. Thorndike plotted these times as curves, and he valued them because any observer "who can tell time" could get the same data.
What is the law of effect?
In the 1911 book Animal Intelligence, Thorndike stated it formally: "Of several responses made to the same situation, those which are accompanied or closely followed by satisfaction to the animal will, other things being equal, be more firmly connected with the situation, so that, when it recurs, they will be more likely to recur". Responses followed by discomfort have their connections weakened.
Next to it he put the law of exercise: a response becomes more strongly connected to a situation "in proportion to the number of times it has been connected with that situation and to the average vigor and duration of the connections".
Does practising one skill train the whole mind?
A common belief, often called "formal discipline", holds that hard subjects exercise general faculties such as attention, memory and accuracy, the way weights build muscle. Thorndike and Robert Woodworth tested the idea behind it in The influence of improvement in one mental function upon the efficiency of other functions (1901). People practised one narrow task, such as estimating the lengths of lines, then were tested on related tasks.
Their conclusion, in the full text, was blunt: "Improvement in any single mental function need not improve the ability in functions commonly called by the same name. It may injure it." They suggested that improvement spreads "only where identical elements are concerned" in the two tasks. Later research has argued over how far this holds, but the warning stands: practising one narrow drill is not the same as getting better at the whole subject.
How can you use Thorndike in your own study?
Close the loop fast. Check each answer soon after you attempt it, not at the end of the week. The law of effect depends on what *closely follows* the response. Our post on feedback timing looks at when feedback helps most.
Practise the real task. If the exam asks you to choose a method in a mixed paper, practise choosing methods in mixed sets, not only solving chapter-end exercises. That respects the "identical elements" finding.
Watch out for rewarding the wrong thing. If you feel satisfied after rereading notes, you are reinforcing rereading. Make the satisfying moment a correct answer from memory instead.
Count repetitions, but spread them. The law of exercise says repetitions matter. Spacing them out over days keeps each one effortful.
For the next step in this line of research, read about B. F. Skinner and reinforcement and the classical conditioning of Ivan Pavlov.
What can a student take from Thorndike's way of working?
He replaced stories about clever animals with timed, repeatable trials, and he was willing to test a belief that most teachers of his day took for granted. Both habits are worth copying: measure your own progress with something as plain as a stopwatch or a score, and test your study methods instead of trusting how they feel.
Quick, specific feedback is the part students most often skip. Fermi's AI tutor checks understanding as it goes and notices where you are stuck, so a wrong step gets caught while the problem is still fresh.
Start today: pick ten problems from three chapters, solve each one, and check it before you move to the next.
