ancient cities

924 Urban Sociology
interests and lifestyles, including those that are
unusual, avant garde, and socially deviant. The
dynamism of the combined diversities in the social
environment of large cities provides encouragement
that allows intellect, offbeat ideas, and subcultures
to flourish, develop, and promote innovations that
eventually diffuse and bring about cultural changes
across society. To the extent that the concept
“community” can be stretched to accommodate
such groupings, this provides an example of what
has been called, by Wellman and Leighton, “liberated”
community, that is, a form of aspatial community
freed from such concepts as “neighborhood.”
The subcultural thesis appears to rescue the traditional
ecological premise while standing the social
isolation argument on its head: Instead, the larger the
metropolitan population is, the greater is the potential
for subcultures to flourish.
Spatial Organization of Cities
Although the evolution of ideas so far described
may be said to be based on an essentially socialecological
premise (and responses to it), urban
ecology has taken on another, narrower meaning
within urban sociology. This narrower tradition
has to do with analyzing the development of the
spatial distribution of land uses within the urban
environment. The assumption that provided the
basis for the development of urban spatial ecology
as a distinct subfield of inquiry is that urban environments
are essentially arenas within which competitive
forces work out a balanced distribution of
land uses. The key characteristics of urban ecology
include tendencies toward localized area specialization
within cities, the central location of services
and activities most in demand, the spatial influence
of prevailing forms of transportation technology,
and the dynamic process of change—invasion and
succession—where the agents of one use take a
district from another segment of the population in
an ordered process of rational evolution. The
underlying force that creates this natural order is
an economic competition where interests with different
levels of resources bid for land parcels based
on compatible adjacent uses and other strategic
factors (e.g., transportation facilities or markets).
Heavy industries, financial districts, entertainment
districts, the residential clusters of different social
classes, and so forth, tend to take on, in city after
city, a rational spatial distribution vis-à-vis one
another and the city’s center.
The most ambitious efforts to develop a universally
applicable predictive model of land-use
patterning are found in early twentieth-century
work such as that of Burgess (concentric patterns
of urban expansion) and Hoyt (radiating linear
patterns of residential growth). The quest to discover
a universal pattern lasted only a decade or
two. The landmark work, generally recognized as
terminating the search for a single predictive
model, is that of Harris and Ullman. They concluded
early in the period of metropolitan expansion
in the United States that no general overall
pattern was discernable. Cities sprawled outward,
producing “multiple nuclei” of similar land uses in
different places, influenced overall by unique features
of local geography. Notwithstanding, there
have been some continued efforts to define broadly
generalizable metropolitan patterns along the lines
of structural functionalist principles. Hawley,
attempting to salvage something of the predictive
principle of urban ecology, argued that researchers
should remain alert to convergent spatial patterns
that indicate an optimizing similarity among metropolitan
areas. The study of urban spatial ecology
has remained a specialized presence in urban sociology,
more recently exploring relationships of
regional domination and specialization among cities,
raising questions of whether metropolitan
sprawl adheres to some overall generalizable pattern
(consistent with Hawley’s recommendation),
and examining whether the gentrification (a form
of invasion and succession) of old residential areas
can be subject to generalized modeling. Overall,
spatial ecology has a diminishing profile within
contemporary urban sociology.
Contemporary Urban Sociology
The contemporary sociology of cities remains distinct
in its traditional focus but shares an interest in
nearly the full range of concerns addressed within
general sociology. Social inequality, majority–minority
relations, economic sociology, political sociology,
and criminology are among the major issue
areas that figure prominently within the subdiscipline.
As these topics merge with urban sociology,
they bring with them their own traditions, in terms
of theories and debates, which sometimes have more