With little or no hesitation, Morgan was able to state that cats and dogs are both examples of the concept of mammal. She was slower to respond when asked whether dolphins and whales were also examples of mammals. This example suggests what?

That although normal animals have no concrete boundaries on their definitions of mammals, cats and dogs are the basic examples and hence easy to remember. As seen through this example, mammals are really difficult to identify on the basis of external features. Not only mammals, but most natural concepts are a little fuzzy when it comes to defining concrete boundaries. There is no single feature that is easy to identify by looking at the animal that serves as a final and binding decision on the type of mammal, whereas the concepts are something more complex.

Cats and dogs though, are taught us to be mammals from whenever we started leaning about mammals. Thus, this explains how prototypes are easy to identify whereas basing on the natural concepts, it might be difficult to identify an animal.