Here is an example summary of this reading selection:

In “The Brains of the Animal Kingdom,” Franz de Waal explains how scientists are revising the way they understand and test animal intelligence. Animals had been considered incapable of higher-order thinking, but this view is largely based on faulty studies that were not designed from an animal’s perspective. As the quality of research has improved, so has our understanding of animals as capable decision makers.

Your summary will differ from this one in the way it is written, but it should include roughly the same information.