"There are two important factors to consider in the emergence of social change. One is that a society develops through changes in its institutions, which are blends of culture and genetically shaped social behavior. The other is that the genes and culture interact. This may seem paradoxical to anyone who considers genes and culture to be entirely separate realms. But it is scarcely surprising from an evolutionary perspective, given that the genome is designed to respond to the environment, and a major component of the human environment is society and its cultural practices."