Instinctive Drift (Breland Effect) refers to...

• A. Instincts, drives, and fixed action patterns might come back in spite of training
• B. A complete loss of all instincts after training
• C. A gradual decrease in fear response
• D. A shift from instinct to learned behavior only

Answer: (A)

The idea being tested is that learned behaviors can be interrupted or overridden by an animal’s natural instincts. Instinctive drift, or the Breland Effect, shows that even after training, instinctual patterns—such as fixed action patterns and innate drives—can re-emerge and influence behavior. That’s why the best answer says instincts, drives, and fixed action patterns might come back in spite of training. For example, a pig trained to deposit coins into a bank may start rooting or washing the coin in water because those instinctual behaviors compete with the trained task. This isn’t a complete loss of all instincts, nor a simple, gradual fear reduction, nor a one-way shift to learned behavior only; it’s the reassertion of innate tendencies that can derail the trained response.