In one episode of the TV show "The Big Bang Theory," the guys are tired of having their conversations get sidetracked. They decide that every time one of them starts talking about something that is off-topic, they will "get their arm hair yanked off." Eventually, Leonard gives up and complains that "negative reinforcement isn't working." Sheldon replies, "I think you mean positive punishment…negative reinforcement is the removal of a positive stimulus." How good is their understanding of operant conditioning?

And then, Sheldon gets the positive punishment part right but he says that negative reinforcement is the removal of a positive stimulus when it really is the removal of a negative stimulus.

Explanation:

In psychology and classical and operant conditioning, we have two different conditions that help people learn: reinforcement and punishments.

reinforcements are stimulus that increase the chances that a certain behavior is repeated in the future. In other words, it refers to something that makes the behavior be more frequent.
punishments are stimulus that decrease the chances that a certain behavior is repeated in the future. In other words, it refers to something that makes the behavior less frequent.

Then, we have 2 different types of punishments and 2 different types of reinforcement:

Positive reinforcement: It consists in presenting a desired stimulus that will increase the chances that the behavior is repeated.

Negative reinforcement: It consists in retiring an undesired or aversive stimulus that will increase the chances that the behavior is repeated (for example, the beeping in the car when we don't use the seatbelt is a negative reinforcement since it is retired the moment we use the seatbelt and it is more likely that next time we'll fasten the seatbelt before to not hear the sound).
Positive punishment: Consists in presenting an undesired or aversive stimulus that will decrease the changes that the behavior is repeated.
Negative punishment: Consists in retiring a desired/positive stimulus that will decrease the changes that the behavior is repeated.

In general we can see that negative implies retiring an stimulus while positive implies presenting an stimulus.

In this example the guys are tired of having their conversations side tracked, so they decide that when someone starts talking about something they will get their arm hair yanked off. Since they want to decrease a behavior, we are talking about punishment.

Now, since they will present an undesired stimulus (having their arm hair yanked off) it will be a positive punishment.

We can see that they are not understanding operant conditioning since this is therefore a positive punishment, Leonard calls it NEGATIVE REINFORCEMENT.

And then, Sheldon gets the punishment part right but he says that negative reinforcement is the removal of a positive stimulus when it really is the removal of a negative stimulus.