Narrative knowledge supports religious organizations, political systems, and ethnic identity. Narrative knowledge can be refined in the development of myth or in case studies of law. Narrative knowledge has been amplified by film and television giving it an extra dimension of visual symbolism. It proliferates because it was the way that biological memory held cultural memory during the time that modern humans evolved their cultural mode of adaptation. The human brain is finely attuned to appreciate and disseminate narrative knowledge.
Narrative knowledge is the oldest form of knowledge and the natural form for most social knowledge.
However knowledge stored in external memory is evolving in a different direction. Externally stored knowledge does not degrade with time like biological memory. Since the mental content of external knowledge exists outside a single human memory it can be worked on and refined by many persons. It can be made more explicit by defining symbols in external form. It can be tested over and over again by many people under many conditions.