Chaining, Shaping, & Instinctive Drift (Intro Psych Tutorial #64)

Summary

In this video, Michael Corayer explains how operant conditioning can be used to shape complex behaviors through techniques like chaining and shaping. Chaining involves linking simple behaviors in a sequence, while shaping gradually rewards successive approximations to teach more complex actions, such as pigeons playing ping pong. However, there are biological limits to conditioning, as shown by the Brelands' experiments with animals like raccoons and pigs, which displayed instinctive behaviors that disrupted the conditioning process. This illustrates that certain natural instincts can override learned behaviors, highlighting the biological constraints on operant conditioning.

Takeaways

• 😀 Operant conditioning uses reinforcement to increase the frequency of behaviors.
• 🔗 Chaining creates complex behaviors by linking together multiple simple conditioned actions into a sequence.
• 🎯 In chaining each behavior is learned separately and reinforcement is given only after the full sequence is completed.
• 🪶 Shaping trains behaviors that would not occur spontaneously by reinforcing successive approximations of the desired action.
• 🏓 Classic shaping example: pigeons were gradually reinforced to approach, touch, push, and then hit a ping-pong ball off a table.
• 🐀 Other shaping examples include rats being trained in multi-step tasks (e.g., carrying a ball to a hoop).
• ⚠️ There are biological limits to conditioning—some behaviors cannot be conditioned away when they conflict with animals’ instincts.
• 🐾 Instinctive drift (instinctual drift) occurs when an animal’s natural instincts override trained behaviors.
• 🪙 Example of instinctive drift: raccoons reinforced for picking up coins began treating coins like food (rubbing/cleaning).
• 🐷 Another example: pigs trained to push discs started rooting them into the ground as if for food.
• 📚 The Brelands’ work (‘The Misbehavior of Organisms’) documents how instinct can disrupt operant conditioning.
• 🔁 Key lesson: chaining and shaping can build complex behavior, but learning interacts with biological predispositions—both matter.

Q & A

What is operant conditioning, and how does reinforcement work in it?

Operant conditioning is a learning process where behaviors are influenced by the consequences that follow them. Reinforcement increases the likelihood of a behavior being repeated, as it provides a rewarding consequence (like a food pellet) after the behavior occurs.

What is the difference between simple behaviors and more complex behaviors in operant conditioning?

Simple behaviors, like pressing a lever, can be easily conditioned and reinforced. However, more complex behaviors, which involve multiple actions or steps, require additional techniques to be effectively learned, such as chaining or shaping.

What is chaining in operant conditioning?

Chaining is the process of linking together multiple simple behaviors to create a more complex sequence. Each simple behavior is conditioned separately, and reinforcement is only provided when the behaviors are performed in a specific sequence, forming a 'chain' of behaviors.

How does the process of chaining work with an example of teaching a pigeon?

In chaining, you would start by conditioning simple behaviors in isolation, such as pressing a lever and pecking a disc. Once those are learned, you would reinforce the pigeon only if it performs both actions in the correct order. You can add more steps to the chain as needed to increase complexity.

What is shaping in operant conditioning, and how does it differ from chaining?

Shaping involves reinforcing successive approximations of a desired behavior. It is used to teach more complex behaviors that don't naturally occur. Unlike chaining, which links already learned behaviors, shaping gradually builds a new behavior by rewarding closer and closer approximations.

Can you provide an example of shaping using pigeons playing ping-pong?

To shape pigeons to play ping-pong, you would first reward the pigeon for getting close to the ping-pong ball. Then, you would reward it for touching the ball, pushing it, and eventually hitting it off the table. This process gradually shapes the pigeon’s behavior until it can play ping-pong.

What is instinctive drift, and how does it limit operant conditioning?

Instinctive drift occurs when animals' natural instincts interfere with conditioned behaviors. Even after conditioning, animals may revert to instinctual behaviors that are incompatible with the desired learned behavior, limiting the effectiveness of operant conditioning.

How did Keller and Marian Breland demonstrate the limitations of operant conditioning?

The Brelands encountered instinctive drift when trying to condition raccoons and pigs. The animals reverted to instinctual behaviors, such as rubbing coins with their paws (raccoons) or rooting with their snouts (pigs), which prevented them from performing the conditioned behaviors.

Why can't operant conditioning always overcome natural animal instincts?

Operant conditioning cannot always override natural instincts because certain behaviors are biologically ingrained in animals. These instinctual behaviors are so strong that they can disrupt the learning process, as seen with the Brelands' experiments.

What biological limits to conditioning are demonstrated in the Brelands' research?

The Brelands’ research shows that animals have innate predispositions for certain behaviors, and when the conditioned behavior is too similar to these instincts, the conditioning process is unsuccessful. This phenomenon is known as instinctive drift, where the animal's natural behavior takes precedence over learned behaviors.