After occurrence of a desirable behaviour, the teacher says 'very good' to the child. She has used:

Question

Accepted Answer

Option 2, "Secondary reinforcer," is the correct answer because the phrase "very good" is an example of a secondary reinforcer. Secondary reinforcers, also known as conditioned reinforcers, are stimuli that acquire their reinforcing power through association with primary reinforcers. In this case, verbal praise like "very good" is not inherently rewarding but becomes reinforcing through its association with other rewards or positive outcomes, such as approval, encouragement, or recognition.

1. **Explanation for Option 2 (Secondary reinforcer):**
   - Secondary reinforcers are learned through experience and are often used in educational settings to encourage desirable behavior. When a teacher says "very good," it serves as a form of social reinforcement that the child has learned to associate with positive outcomes, such as feeling valued or motivated. This makes it an effective tool for reinforcing behavior in a classroom setting.

2. **Explanation for why other options are incorrect:**

- **Option 1 (Primary reinforcer):**
     - Primary reinforcers are stimuli that are naturally rewarding and do not require any learning to be effective, such as food, water, or warmth. The phrase "very good" does not fulfill any basic biological needs and is not inherently rewarding without prior learning and association, making it a secondary, not primary, reinforcer.

- **Option 3 (Negative reinforcement):**
     - Negative reinforcement involves the removal of an unpleasant stimulus to increase the likelihood of a behavior being repeated. Saying "very good" does not involve removing any negative or unpleasant stimulus; instead, it adds a positive stimulus (praise) to reinforce behavior, which aligns with positive reinforcement rather than negative reinforcement.

- **Option 4 (None of the above):**
     - Since "very good" is clearly a secondary reinforcer, as explained, Option 4 is incorrect. The phrase is a learned form of reinforcement that effectively encourages desirable behavior, fitting the definition of a secondary reinforcer.

In summary, Option 2 is the correct answer because "very good" is a secondary reinforcer, learned through association with other positive outcomes, and effectively used by the teacher to reinforce desirable behavior in the child.