Abstract

Erect posture and large brain are two of the most significant anatomical traits that distinguish us from nonhuman primates. But humans are also different from chimpanzees and other animals, and no less importantly, in their behavior, both as individuals and socially. Distinctive human behavioral attributes include tool-making and technology; abstract thinking, categorizing, and reasoning; symbolic (creative) language; self-awareness and death-awareness; science, literature, and art; legal codes, ethics and religion; complex social organization and political institutions. These traits may all be said to be components of human culture, a distinctively human mode of adaptation to the environment that is far more versatile and successful than the biological mode. Cultural adaptation is more effective than biological adaptation because its innovations are directed, rather than random mutations; because it can be transmitted "horizontally", rather than only "vertically", to descendants; and because cultural heredity is Lamarckian, rather than Mendelian, so that acquired characteristics can be inherited. I explore ethics as a distinctive human trait. The question whether ethical behavior is biologically determined may refer either to the capacity for ethics (i.e., the proclivity to judge human actions as either right or wrong), or to the moral norms accepted by human beings for guiding their actions. I will propose: (1) that the capacity for ethics is a necessary attribute of human nature; and (2) that moral norms are products of cultural evolution, not of biological evolution