What distinguishes human beings from other animals, even other apes, is our qualitatively distinct abilities to think, reason, and communicate with others.
Cognitive psychology is the scientific field devoted to studying our special mental capacities.
That is, the goal of cognitive psychology is to understand the nature of human intelligence and how it works. Why are huskies, golden retrievers, daschunds, dalmations, etc. And so on and so on. Cognitive psychology is a laboratory science. That is, we learn about how the human mind works by conducting controlled experiments.