Rewards and Penalties
A reward is an object or event that an animal will approach and work for.
Behavior as the Test
When studying learning, the word reward does not simply mean something that people call a prize or something that appears pleasant to a human observer. A reward is an object or event that an animal will approach and work for. The definition is behavioral: we examine what the animal does.
Imagine observing an animal in a learning experiment. The animal moves toward one event and performs an action to obtain it, while ignoring or avoiding other events. The important question is therefore not whether people label the event as desirable. The important question is whether the animal approaches it and works to obtain it.
To identify a reward, look for both parts of the behavior: approach toward the object or event and work performed to obtain it.
Primary Rewards and Innate Value
Primary rewards are innate. Their rewarding quality arises from nervous-system machinery shaped by evolution rather than from the individual animal's learning history. They are connected with survival, reproduction, and events that predicted reproductive success over ancestral history.
Calling a primary reward innate does not mean that every response to it is identical in every situation. It means that the reward quality is supplied by the animal's evolved nervous-system machinery. The animal does not first need to learn that this category of event can support survival or reproduction before the event can function as a reward.
The key contrast is the source of the reward quality: primary rewards receive it from evolved nervous-system machinery, whereas secondary rewards acquire it through individual learning.
From Neutral Stimulus to Secondary Reward
A secondary reward does not begin with the same built-in status as a primary reward. An individual animal learns that a stimulus or event predicts a primary reward. Through that prediction, the stimulus acquires rewarding quality. A stimulus can also become secondary by predicting another secondary reward.
The important change is not necessarily a physical change in the stimulus. The change is in its learned significance for the animal. Before learning, the stimulus does not have the same reward status as a primary reward. After the animal learns that it predicts a primary reward, the stimulus can become something the animal approaches and works to obtain.
A Learned Predictive Stimulus
Suppose an animal repeatedly experiences a previously neutral signal followed by an event connected with primary reward. Later, the animal approaches the signal and performs an action to obtain it. How should the signal be classified?
Observe the behavior: The animal approaches the signal and works to obtain it, so the signal meets the behavioral definition of a reward.
Identify the source of its value: The signal did not begin with the same built-in status as a primary reward. Its value developed because the animal learned that the signal predicts a primary reward.
Classify the signal: Because its rewarding quality was acquired through individual learning and prediction, the signal is a secondary reward.
The signal is a secondary reward because it acquired reward quality by predicting a primary reward.
Comparing the Two Categories
| Question | Primary reward | Secondary reward |
|---|---|---|
| Where does rewarding quality come from? | Innate nervous-system machinery shaped by evolution | Individual learning and prediction |
| What is it connected with? | Survival, reproduction, or events that predicted reproductive success over ancestral history | A primary reward or another secondary reward that it predicts |
| Source example | The source describes the category through survival and reproduction | Money |
| What must be explained in an answer? | Why the value is innate | What the stimulus predicts and why that learned relationship gives it value |
The classification depends on how the reward quality arose, not merely on whether people call the object desirable.
Money illustrates the secondary category because its rewarding quality is learned rather than supplied as an innate primary reward. A complete answer should therefore say more than “money is secondary.” It should explain that money acquires rewarding quality through a predictive relationship with primary or other secondary rewards.
Mistakes in Classification
Classifying an object as a reward because a person calls it a prize.
The definition depends on whether the animal approaches the object or event and works to obtain it.
Fix:
Use the animal's approach and work as the behavioral evidence.Saying only that money is secondary.
The category is incomplete without the reason that its rewarding quality is learned.
Fix:
Explain that money acquires rewarding quality through a predictive relationship with primary or other secondary rewards.Treating every reward as innate.
Secondary rewards acquire their quality through individual learning and prediction.
Fix:
Ask whether the reward quality comes from evolved machinery or from a learned predictive relationship.Defining a secondary reward only by its physical appearance.
The defining feature is how the stimulus acquired reward quality, not its physical form.
Fix:
Identify what the stimulus predicts and whether that relationship was learned.
When answering a classification question, use a two-part structure: name the category, then give the reason. For a primary reward, explain its innate connection with evolved nervous-system machinery. For a secondary reward, explain the learned prediction that gives the stimulus or event its rewarding quality.
Classify the Candidate
An animal repeatedly experiences a stimulus that predicts another rewarding event. Later, the animal approaches the stimulus and performs an action to obtain it. Classify the stimulus as primary or secondary, and justify your answer using both the animal's behavior and the source of the stimulus's reward quality.
Hints
- First check whether the animal approaches and works for the stimulus.
- Then ask whether the stimulus's value was innate or acquired through prediction.
- Give both the category and the reason.
Practice Answer
Classify a stimulus that an animal approaches and works for after learning that it predicts another reward.
Behavior: Approaching and working for the stimulus shows that it functions as a reward under the behavioral definition.
Learning history: The stimulus acquired its rewarding quality through a predictive relationship rather than through the same innate status as a primary reward.
Conclusion: The stimulus is a secondary reward.
It is a secondary reward because the animal learned that the stimulus predicts another reward.
Key Takeaways
- A reward is an object or event that an animal will approach and work for.
- Primary rewards are innate because their rewarding quality arises from nervous-system machinery shaped by evolution.
- Primary rewards are connected with survival, reproduction, and events that predicted reproductive success over ancestral history.
- Secondary rewards acquire rewarding quality through individual learning and prediction.
- A strong classification answer names the category and explains whether its value is innate or learned through a predictive relationship.
Key Takeaways
- A reward is identified by the animal's behavior: it approaches the object or event and works to obtain it.
- Primary rewards have innate value supplied by evolved nervous-system machinery.
- Secondary rewards gain value when an animal learns that a stimulus or event predicts a primary or another secondary reward.
- Money is a source example of a secondary reward because its rewarding quality is learned.
- To classify a reward correctly, state both its category and the reason for that category.