From nonhuman to human mind - What changed and why?

Two questions regarding the human mind challenge evolutionary theory: (a) What features of human psychology have changed since humans' lineage split from that of the other apes such as chimpanzees and bonobos? And (b) what was the process by which such derived psychological features evolved (e.g., what were the selection pressures)? I review some of the latest research on chimpanzee and canine psychology that allows inferences to be made regarding these questions.