This laid out a basic framework for conditioning / learning. It showed that the dog was doing more than just following its biological programming to drool when consuming food. Its brain learned that the bell meant food was coming, and its body responded appropriately.

This lead to the... theory?... of classical conditioning, which I ignorantly boiled down to just a few functional components to help me remember.

Reinforcement vs Punishment. Pretty straightforward.
- Reinforcements are good stuff (treats) that cause behaviors (drooling) to appear more frequently.
- Punishments are bad stuff that make behaviors go away.
Positive vs Negative.
- Positive is adding the reinforcement or punishment when the desired behavior presents. Positive reinforcement encourages the behavior. Positive punishment dissuades it.
- Negative is removing the reinforcement or punishment. Negative reinforcement is removing what had been a constant reward, like attention, in response to a target behavior to dissuade it. Negative punishment is basically torture, finally stopping the bad thing when the desired behavior presents, encouraging it.
Variable vs... Constant? Forgetting...
- variable positive reinforcement is sometimes rewarding the behavior, like a slot machine. This leads to slower development of the trained behavior but with exponential growth. It's much more powerful training in the long term.
- Constant(?) reinforcement, giving the reward every time the behavior presents, gives linear progress. The behavior will train more quickly but less reliably. When the reward disappears, the behavior diminishes quickly, but with variable training the subject is used to sometimes not being rewarded and the behavior will persist.

Classical conditioning is very powerful. A famous example I remember is using it to teach a squirrel to water ski. It works well on simple minds, and it works to a degree on almost any mind. It's often drastically over-applied to explain or try to train any behavior in any being, which is probably why it feels like you hear about Pavlov's dog everywhere. People use it as a metaphor to try to explain virtually any behavior.

But developed humans are much more complicated than that. I loosely remember that operant conditioning was kind of the next level up and pretty well explained behaviors in slightly older kids, and even that wasn't the most advanced model I learned. It's the most advanced one I remember though. If memory serves, adult human behavior is still too complex to be explained with any simple model, a mystery we're still unraveling.

I'm trying my best to regurgitate lessons I learned decades ago, so give me a break and take it all with a grain of salt.

Long story short, you hear about Pavlov's dog everywhere because behaviorist models of learning built on classical conditioning are the best most people have, and they use it to explain any behavior despite it being woefully insufficient in most cases.

To learn more, maybe look for some academic psychology books or just information about classical conditioning generally.

That's the best I got. Sorry for any misinformation. Good luck on your search.