spread contagiously, especially in the era of visual media and the Internet, when mil-
lions of people have almost instantaneous access to outlets that follow and promote
the latest trends. In 1964, the Beatles first appeared on the Ed Sullivan show, an
immensely popular variety show watched by millions of Americans, and their
longer haircuts immediately caused controversy. But within a few months, thou-
sands of young American men were wearing their hair in a similar style and donning
“Nehru jackets” that the Beatles often wore while performing. The British quartet
had changed American cultural standards and behavior almost overnight. Before
the advent of mass visual media, contagious diffusion of ideas or practices generally
required person-to-person contact. A second example of this type of diffusion is the
spreading of proselytizing religions that seek mass conversion of a population. Both
Islam and Christianity historically diffused when a few believers from these faiths
encountered nonbelievers, converted them, and they in turn converted additional
followers in a classic sequence of contagious diffusion based on personal contact.
One of the most influential theoreticians in cultural geography regarding the
concept of diffusion was the late Torsten Hagerstrand, who developed statistical
models that illustrate how diffusion operates in space. His theory rests heavily on
a core and periphery framework, which he employs to explain why new ideas
and cultural trends, which could possibly arise at any point in space, tend to con-
centrate and thereby create core areas and corresponding peripheral regions. A
neighborhood effectalso influences the movement of cultural traits through space
at the local scale, when an individual acquires the new trait and then influences
those near him, including his family and immediate neighbors. One of the short-
comings of the Hagerstrand approach is its failure to explain why many cultural
attributesfailto diffuse, especially in an era of global communication and cultural
exchange. Nevertheless, Hagerstrand’s ideas continue to be the focus of much
discussion and debate, and provide a conceptual foundation for further study of
diffusion and its effects.Cultural Ecology
A theoretical perspective common to cultural geography and derived from
anthropology that focuses on the relationship between human activity and environ-
mental conditions. Early theory in cultural ecology evolved from anthropological
studies that were concerned with how human societies are changed due to altera-
tions of the natural environment. Thus, early on, cultural ecology as a theoretical
approach sharedsomecommon elements withenvironmental determinism,
although the cultural ecologists as a whole rejected the idea that environmental82 Cultural Ecology