What is a supernormal stimulus?

A supernormal stimulus refers to an exaggerated or enhanced version of a sign stimulus that is more effective at eliciting a fixed action pattern (FAP) than the original stimuli occurring in nature. This concept is often used in the study of animal behavior. For example, in experiments with certain bird species, researchers have found that birds can be more strongly attracted to a larger or more vividly colored egg than to their own naturally sized or colored eggs. This shows that the supernormal stimulus can evoke a stronger response than the normal stimulus present in the environment.

In contrast, the other options describe scenarios that do not accurately capture the essence of what a supernormal stimulus is. A natural stimulus that fails to trigger a FAP does not fit the definition since a supernormal stimulus needs to be effective in triggering behavioral responses. Similarly, a weaker version of a sign stimulus does not convey the concept of supernormal stimuli, which are actually enhanced, not weaker. Lastly, the idea that a supernormal stimulus is an enhanced version that is less effective is contradictory, as the term inherently suggests that it produces a stronger response than the sign stimulus. Thus, the correct understanding of a supernormal stimulus helps clarify its role in behavioral studies and its impact on instinctual animal behaviors.