The evolution of the human brain involved a series of genetic events that did not occur in other animals. These led to a highly complex organ that is unique to humans and sets us apart from other animals. The human brain gives us the ability to learn and use language, unlike any other species in the animal kingdom. It also enables us to store complex memories and gives us a sense of self-awareness, both of which are unrivalled.
Joly O et al. Processing of vocalizations in humans and monkeys: a comparative fMRI study. NeuroImage 2012;62(3):1376-89.