Before my fellow first years jump on me, no they're not the same thing :( I know most text books teach them as being the same thing, but most text books also confuse the Yerkes-Dodson law and the Hebb's version of it and don't even mention Hebb and for some reason my course thinks these little details are incredibly important and I have to learn them. So I'm hoping some of you have studied this way as well since I can't find anything about the differences online to double check my understanding. Can you? Here is how I understand it Instrumental conditioning (Thorndike): The important thing in instrumental conditioning is the situation (stimulus) and the response, Centers on the law of effect Operant conditioning (Skinner) The important thing in operant conditioning is the response and the reinforcement. Centers on the law of reinforcement. This seems absolutely mad to me. Of course there is a reinforcement in Thorndike's experiments, otherwise the cat would just curl up and go to sleep inside of the box. Of course there is a situation in Skinner's experiment, otherwise what would we study? All three things seem equally important in both. But I guess with instrumental you're thinking "how fast can the cat get out of the box"/" can the cat learn / how long does it take the cat to learn" While with operant you're thinking "what cool things can I get the pigeon/my pets to do?" It's also possible that the book is just really badly written, and when they say "Blah blah blah Thorndike blah blah blah - this is known as instrumental conditioning" and then they go on to say "Blah blah blah Skinner blah blah blah - this is known as operant conditioning" That they actually mean "all of this is known as instrumental or operant conditioning" . Thanks! Edit: Oh dear, sorry for the angry tone of this message. It's not the poor book's fault.