Many methods are used to assess intelligence and its evolution. These include behavioral measures, which may involve naturalistic observation or analyzing responses in laboratory experiments; artifactual measures, which involve analysis of tools, art, and so forth; and anatomical/neurological measures. This chapter discusses intelligence in our closest relatives that include the great Apes such as chimpanzees, bonobos, gorillas, and orangutans. It also addresses the question of why human intelligence evolved, and whether it is still evolving. Sexual selection, group selection, and the Baldwin effect have also been implicated as playing a role in shaping intelligence. Another possibility derives from the theory that culture constitutes a second form of evolution. By understanding the evolutionary origins of human intelligence, we gain perspective on pressing issues of today and are in a better position to use our intelligence to direct the future course of our species and our planet.