TWO VIEWS OF DIFFUSI
JAMES M. BLAUT
ABSTRACT. The Hagerstrandian view of diffusion, now prevalent, is too narrow:
narrow in its reliance on “information,” a weak and elusive variable, and narrow
in its space-time scope. A broader view is exemplified by the work of cuitural
geographers like Kniffen. There is a need for a dialectical exchange between the
two kinds of theoreticians. Eventually, this should lead to a more useful theory.
EFORE diffusion, a landscape is empty of
B
a given trait. After diffusion, the trait has
suffused throughout the landscape. So diffusion
of the newer models are offsprings of Hagerstrand’s classic Model 111, the reasoning behind
them is still mainly Hagerstrand’s, and the cennarrowly conceived is merely a transition. Why tral problem Is still the kind of expansion difdeem it so important?
fusion with which Hiigerserarid was concerned
Associated with this narrow conception is a in his major work. We can with justice identify
narrow theory. Diffusion is often said to be the enterprise as a whole with Hagerstrand’s
explainable in terms of a single, simple variable: name. I will use the term, “Hagerstraridian difinformation. But diffusion is an incident of cul- fusion,” to indicate this problem and theory,
ture change, and culture change is an exceed- and to distinguish it from another, larger, probingly complex process. Why oversimplify?
lem and another kind of theory.
So we may ask: Is diffusion research too narHagerstrand was clearly aware, as some
row? Is it overly concerned with the ephemerae others are not, that spatial form is the result
of adoption? Is it simplistic? Should we not of cultural process. In attempting LO explain
embrace a broader view: a conception of dif- the evolving form of a diffusion, he adopted a
fusion as the general process which includes the customary theoretician’s strategy of isolating a
infusion and suffusion of traits in some regions single component in the underlying process, a
and their nondiffusion in others? Perhaps the variable which possesses two characteristics:
one view is merely a part of the other. If so, it appears to be important-that is, high in exthen spatial models of expansion diffusion planatory power; and it is amenable to matheshould be grounded in the same body of theory matical expression. The component he chose
as general models of geographic (and culture) was information, or, more properly, the comchange. But they are not, and-mainly for this munication of information about an innovation.
reason-the
narrow view has not been very Thus he arrived at the following axiom (the
helpful.
phrasing is Allan Pred’s) : 2
The term, “spatial diffusion theory,” has
Geographic expressions of human behavior . . .
come to be associated with a fairly specific
must be viewed in terms of the information available to the individual decision-maker . . and
enterprise: the attempt to explain the spatial
thereby analyzed in terms of the “social network’
spread of an innovative trait in a region, usually
of interpersonal communications through which the
with the help of mathematical models. The
information circulates.
problem is thus diffusion in the narrow, or transitional, sense. The models are rather like two- In Hagerstrand’s theory, therefore, the motive
dimensional adoption curves, some probabilis- power for diffusionlies in the spread of informatic, others deterministic. The earliest models and tion; other cultural variables are relegated to the
the basic arguments were introduced more than status of resistance factors, or barriers, and for
twenty years ago by Torsten Hagerstrand.l Most the most part they are considered to be randomly distributed and rather unimportant.
Dr. Blaut is Professor of Geography at the Univer- Hagerstrand was justified in using this axiom
~
sity of lllinois at Chicago Circle in Chicago, IL 60680.
1 Torsten
Hagerstrand, Znnovation Diffusion as a
Spatial Process (Chicago: University of Chicago
Press, 1967), translated and with a postscript by Allan Pred. (Originally published in 1953.)
2 Hagerstrand, op. cit., footnote 1, p. 300.
ANNALS OF THE ASSOCIATION OF AMERICAN GEOGRAPHERS Vol. 67, No. 3, September 1977
@ 1977 by the Associehon of American Geographers. Printed in U.S.A.
343
344
JAMES M. BLAUT
September
fact, given a space of its own-and is divided
into explicit taxonomic units which diffuse separately. Secondly, we are committed to a disturbingly elitist theory concerning the causal
efficacy of knowledge-more precisely, of cognitive learning-as against the role of such other
cultural elements as values, social structure, and
economic conditions. I am suggesting that a
diffusion model which isolates information (in
a sense, knowledge) as an independent, universal variable is not a simulation of the real
world of geographic change; it is a simulation
of a particular psychological (and psychologistic) model of the world, a model which is also
highly ethnocentric. Let me illustrate:
1) In a Hagerstrandian diffusion process, a
discrete bit of information-that which relates
to the innovative trait-is flowing in some manner across a landscape. What makes this bit of
information a meaningful message? We have to
postulate an underlying psychological landscape, a uniform cognitive region. It would be
absurd to imagine that the cognitive region was
built up by wave after wave of prior diffusion,
each wave consisting of a discrete bit of information. If this were realistic, then cognitive
structures would in fact be structureless: minds
simply would be heaps of disjointed bits of
knowledge, like apples in a basket. The acquisition of knowledge would then have little to do
with social organization: information would
come from nearest neighbors, not from fathers,
mothers, and schools. It seems, therefore, that
Hagerstrandian diffusion processes are secondary and contingent events; that most knowledge
diffuses by other means. They cannot lie at the
core of a fully formed theory of the diffusion of
knowledge, much less the diffusion of material
3 L. A. Brown, “Diffusion of Innovation: A MacroView,” Economic Development and Cultural Change, things.
Vol. 17 (1969), pp. 189-211; Allan Pred, in Hager2) In a Hagerstrandian diffusion process,
strand, op. cit., footnote 1, pp. 309-10; John C. Hudson, “Some Properties of Basic Classes of Spatial- knowledge plays a basic causal role. For HagerDiffusion Models,” in Harold McConnell and David strand‘s investigations it was “the most imporYaseen, eds., Perspectives in Geography, I: Models tant driving force behind the innovation diff uof Spatial Variation (DeKalb, Illinois: Northern Illisions under study.”4 Again we must ask how
nois University Press, 1971 ), pp. 47-48; Torsten
Hagerstrand, “What About People in Regional Sci- widely the principle applies. In psychological
ence?’ Papers of the Regional Science Association, theory, cognitive models rarely are divorced
Vol. 21 (1970), pp. 7-21. In 1971, Brown and Cox from overt behavior; learning is closely related
could assert that “all theories of innovation diffusion
stress the role of communication defined narrowly in to concrete experience. In anthropological
terms of the passage of information,” and this state- theory, personality variables are rather generally
ment would still be correct (for theories in the Hager- considered to be dependent on structural varistrand tradition). L. A. Brown and Kevin Cox, “Empirical Regularities in the, Diffusion of Innovation,” ables, social, economic, ecological, and so on. If
for the problem at hand: he was working (in
the rural heartland of Sweden) with a culturally
uniform space, with a population of potential
adopters who possessed quite generally the
technical and economic means for adoption,
and with a set of innovations which had demonstrable utility. Information was, in essence, the
only missing variable, the only element needed
to set the diffusion process in motion. In fact,
Hagerstrand was dealing with something approaching the classical Extension Service problem as one encounters it throughout the rural
West. This, immediately, should give us pause.
Extension services have had little success in the
non-Western world, and they had nothing to do
with two million years of prior diffusion.
Diffusion theorists in the Hagerstrand tradition still hold tenaciously to the information
axiom in spite of cautions expressed by Brown,
Pred, Hudson, and others, and implicitly by
Hagerstrand himself (who writes eloquently of
the need to consider man as a complex culturebearer) . 3 Cautions are not enough. Serious difficulties arise whenever efforts are made to generalize the information-based Hagerstrand
theory, or to apply it in realms and epochs
which are culturally distant from the modem
Western world.
These difficulties stem from the kinds of implicit theories which we must adopt when we
try to isolate the category “information” and
treat it as an independent variable for a general
(hence cross-cultural) theory. We are committed, first of all, to an archaic, in fact Platonic,
theory of knowledge, according to which knowledge is separated from the material world-in
Annals, Association of American Geographers, Vol.
61 (1971), p. 557.
4
Hagerstrand, op. cit., footnote I, p. 1G1.
1977
VIEWSOF DIFFUSION
knowledge is ordinarily a minor or dependent
variable in culture change, this form of causal
theory cannot be very widely generalized.
3 ) Diffusion models which are grounded in
the assumption that the spread of knowledge
is a basic operating variable are, paradoxically
enough, somewhat anti-intellectual. The precondition for learning is ignorance. One assumes
that ignorance is the obstacle to adoption-that
is, to culture change. One assumes, as well, that
change must come from a teaching (or telling)
activity. All of this is in effect a denial that
ordinary humans are intelligent enough to seek,
demand, and acquire the needed knowledge
when the other conditions for adoption are
already present. Thus it is not surprising to
find that information-based diffusion theory,
in application, rather consistently identifies successful diffusion with exceptional individuals
(“change agents,” “progressive farmers,” and
“cosmopolites”), and with information-disseminating institutions.5 Nor is it surprising to find
that this kind of diffusion research in nonWestern areas is closely identified with an
ideology of development which emphasizes technical assistance rather than control of resources.6When peasant farmers do not innovate,
however, it is not because they are afflicted with
technological ignorance, or with a traditional
5 Terms like these, along with their antonyms (e.g.,
“laggards,” “localites,” and “passive adopters”) derive mostly from the folklore of the North American
agricultural extension movement and its disciplinary
offspring, rural sociology. Many such terms, along
with the elitist social theory lying behind them, seem
to have entered geography through the immensely
influential writing of the rural sociologist Everett M.
Rogers. See Everett M. Rogers and F. F. Shoemaker,
Communication of Innovations (New York: Free
Press, 1971).
6This ideology is most explicit in the writings of
rural sociologists who, for obvious historical reasons,
are more often involved in rural development work
than are geographers. However, the ideology is apparent in the work of such geographers as Gould, Riddell, and Lentnek. See in particular J. Barry Riddell,
The Spatial Dynamics of Modernization in Sierra
Leone: Structure, Diffusion, and Response (Evanston,
111.: Northwestern University Press, 1970); also see
Peter Gould, “Tanzania 1920-1963: The Spatial Impress of the Modernization Process,” World Politics,
Vol. 22 (1970), pp. 149-70, and Barry Lentnek,
“Latin American Peasantry in Transition to Modern
Farming,” Proceedings of the Conference of Latin
Americanist Geographers, Vol. 1 (1970), p. 163: “The
focus in any study of the peasant from a developmental standpoint is upon the role of ‘outside’ contacts of local society.”
345
mentality. Most often it is because they cannot
afford to do SO.^
There are two sets of cultural circumstances,
often conjoined, in which information-based
diffusion models are likely to prove powerful
and in which their simplifying assumptions are
in accord with culture theory and with the real
world. They may be important, first, in a cultural system which defines the flow of information as an important cultural process which
institutionalizes the spread of new knowledge
as a mechanism for pattern-maintenance or purposive culture change. Second, such models
c!early wi!l be important under those conditions
where pressure for change is already present
and all the requisite factors have been mobilized, save one: the factor of information.
The most important fact about innovation
diffusion in the non-Western world is its rarity.
By this I mean that nondiffusion is very much
more common than diffusion in the case of all
those productive traits which we associate with
what is called “development.” As development
is rare, so is diffusion. The second most important fact is that diffusion, when it occurs, does
not tend toward the form predicted in Hagerstrandian diffusion models. Again let me illustrate:
1 ) When new technology is rejected, the
explanation has little to do with lack of information, and with those putative barriers to information flow which are often postulated by
development theorists-lack
of “achievement
motivation,” lack of “creativity,” “limited
wants,” and adherence to “tradition.”s Consider
the case of Chinese market-gardeners in Singa7 See, in this connection, Keith Griffin, The Political
Economy of Agragian Change: A n Essay on the Green
Revolution (Cambridge: Harvard University Press,
1974) and A. G. Frank, Sociology of Development
and Underdevelopment of Sociology (London: Pluto
Press, 1971). An example of empirical research
demonstrating the relatively limited significance of
information-related variables is Ronald D. Garst’s
“Innovation Diffusion Among the Gusii of Kenya,”
Economic Geography, Vol. 50 (1974), pp. 300-12.
David C. McClelland and D. G. Winter, Motivating Economic Achievement (New York: Free Press,
1969); Everett Hagen, On the Theory of Social
Change (Homewood: Dorsey Press, 1962); and
George M. Foster, “Peasant Society and the Image of
the Limited Good,” American Anthropologist, Vol.
67 (1965), pp. 293-315. For a critique, see Frank, op.
cit., footnote 7.
*
346
JAMES M. BLAUT
pore who were urged to adopt artificial fertilizers in place of the traditional, and very costly,
organics. They refused to do so on grounds that
artificials do not maintain soil structure, perhaps
the key pedological factor in this farming system. They possessed more, or better, information than the agricultural officer^.^ Consider
also the case of tobacco farmers in Puerto Rico
who, for two generations, have refused the
urgent advice of U.S. Department of Agriculture experts to adopt contour drainage and
abandon a favored soil conservation system involving diagonal, criss-cross drains. The farmers
correctly point out that contour drainage leads
to land slips; in respect to subsoil processes such
as solifluction, the farmers’ ethnopedology is
clearly superior to official (and alien) ethnopedology. The farmers are aware (as the experts
perhaps are not) of the technological advantages of sealed contour drains, but they are
aware also that the cost is prohibitive. I think
we can generalize as follows: technological innovations tend to be rejected, not through ignorance, but through incompatibility with the
existing cultural system as a whole. The system
often is oppressive, exploitative, and bitterly
disliked. Farmers will suggest other remedies,
less likely to diffuse in the Hagerstrandian manner, but more likely to work.
2) New technology at times is adopted so
readily, and spreads so rapidly, that the process
can best be described as “instant innovation.”
Certainly this was the case with the postColumbian diffusion of New World crops,
notably tobacco, and with many of the technological transfers between China and the West.
It can on occasion be observed in modern
peasant agriculture. In the Guayana region of
southeastern Venezuela, where cassava (Manihot utilissima) is the staple crop and cassavabread is the staple food, farmers traditionally
prepared the bread with an almost pre-Columbian technology of graters, presses, and griddles.
This is a commercialized farming system, and
much of the cassava was until recently sent in
unprocessed form to urban bakeries. There, the
bread was prepared by means of a postindustrial technological complex involving a gasoline
engine, an iron grating mill, elaborate ovens,
9 J. M. Blaut, “Chinese Market Gardening in Singapore: A Study in Functional Microgeography,” unpublished doctoral dissertation, Louisiana State University, 1958, p. 314.
September
and a large wooden press, the whole forming a
material-culture complex with a distinctive
name, el motor (after its most distinctive element). Today, nearly every farm within reasonable access of urban markets has acquired el
motor for itself, in spite of the high capital cost
and exotic technology. The diffusion has occurred over several thousand square miles in
a single generation. The explanation is to be
found in the rapid growth of Ciudad Guayana
as a market for food and a source of off-farm
employment. Farms in the area were not landlord-ridden, hence windfall income could and
did lead to capital accumulation, and capital
accumulation led to technological change and
thence to more income and more change. An
immense amount of new technological knowledge was somehow acquired, without official
help, and in a very short period of time. Initial
ignorance proved not to be a barrier.1° In general: when the socio-economic conditions for
adopting a new innovation have been fulfilled,
the needed information will be sought. No doubt
the flow of information about el motor in rural
Guayana can be modeled in the Hagerstrandian
manner, but such an enterprise would throw
very little light on the diffusion of the traitcomplex itself.
Most of the recorded instances in which new
technology has diffused among Third World
farmers in some measurable relation to the
spread of information can be assigned to either
of two cases, both of which support my argument. In the first and more common case, the
new technology has diffused in peasant space,
but not in peasant culture. The information
fields are lattices among wealthy farms, and
between wealthy farmers and government agencies, marketing and supply firms, and the like.
This is really a reproduction of the Hagerstrandian diffusion process as it occurs in developed areas. In the second case, one finds a
simple methodological error. The diffusion of
an innovation is recorded, the correlative existence of information-fields is modeled, and the
latter is assumed, erroneously and without evidence, to account for the former. Invariably,
however, there are other variables, also with
correlative distance-decay functions, and the
choice of information as the operant variable
1oData are from my unpublished reports to the
Venezuelan Government (Corporaci6n Venezolana de
Guayana), 1963-65.
1977
VIEWSOF DIFFUSION
is a matter of theoretical bias, not empirical
discovery. In both of these cases, diffusion has
occurred primarily in the elite sector, not among
ordinary peasants. In peasant agriculture as a
whole, there has been virtually no important
and useful technological change in recent times.
Were it otherwise, the underdeveloped world
would be developing.
We can return now to our first question: Why
is it important to model the space-time spread
of an innovation in a region? It is indeed important-if the models have explanatory power
and if they throw some light on the forces of
culture change, but there are many problems.
Let me illustrate once again:
1) We do not yet have a really satisfactory
theory of cultural causation, hence we have no
basic process to simulate in a model. Assuming
that the simulation of culture as a discrete set
of variables is possible, which of these variables
shall we choose as operators? Which shall we
neglect? Cognition, or knowledge, is an interesting variable where private and public information flow is the mechanism for generating a
specific, prefigured form of culture change. This,
however, is a moderately rare event. It is peculiarly characteristic of the postindustrial Western world (if we exclude the poor, the ghettodwellers, the migrant laborers, and the peasants
of Calabria). When we try to fit our information-based models to data from the non-Western
or preindustrial world, we are saying, in effect,
“that which works here works everywhere.”
Our models thus become lenses through which
we focus our ethnocentric biases.ll Does this
indictment extend to all other candidate-variables? Thus far, I would say, it does. As to the
future, I do not know.
2) Simply defining our variables is yet another problem. I doubt whether we can uncover
an operational definition of “information” outside of the culturally specific institutions and
forms of communication in which it is embedded. The problem arises with every dimension of culture. I am something of an economic
determinist, and I suspect that more can be
explained with the economic variable than any
other. But what is this variable? In practice,
it dissolves into questions of class, power, tenure, material resources, and the like-each
a
11J. M. Blaut, “Geographic Models of Imperialism,” Antipode, Vol. 2, No. 1 (1970), pp. 65-85.
347
complex variable in itself. Perhaps one can explain the processes of diffusion (and, more
crucially, nondiffusion) in the peasant world
in terms of economic relations, but no way has
been found as yet to simulate these relations for
a peasant economy.
The choice of variables need not be ethnocentric, and one can always try to work with extracultural analogs (epidemiology, wave mechanics, and the like) and with general systems
models. In principle we can model the spread
of any diffusion, and the question will be, how
far can a given model be generalized? How
much of the real world does it interpret, and
how well? There is a more fundamental problem concerning the relationship between an explanation of the spatial form of diffusion and
an explanation of diffusion itself. We asked at
the outset whether the former is a subcomponent of the latter. If so, then any theoretical
success with spatial models should be a sign%cant step toward a general theory of diffusion.
But there is good reason to doubt whether an
explanation of the evolving form of diffusion
within a region is important in explaining why
diffusion takes place at all.
When we say that culture is organized as a
system, we imply that culture change involves
a structural change throughout the system.
Structural change is not strictly instantaneous,
so we can describe and model the evolving
process even in complex structures (as is done,
for instance, in models of hierarchical diffusion). But structural change may be theoretically instantaneous, because for any given level
and unit of structure, the structural entity may
be broken as a spatial whole and quickly or
slowly reformed. There is a fundamental differ-.
ence between the kind of theory which accounts
for the shattering or crumbling of a cultural
structure and the kind which traces, as it were,
the spreading fractures and the dispersing fragments. In Hagerstrand’s landscape, the structural units were individual, microgeographic,
entrepreneurial decision-makers. A theory of
structural change for this granular region can
be said to coincide with a theory of spatial diffusion within the region. This is a rare situation
in cross-cultural terms; the pure case would be
a sort of Adam Smithian landscape, one totally
without macrostructure. Contrast this with the
condition of peasants (or, for that matter,
ghetto-dwellers ) , whose decision-making power
348
JAMES M. BLAUT
is limited by a general exploitative structure at
the macrogeographic level. The cases which I
have cited of diffusion and nondiffusion in peasant culture involved an all-or-none process in
space: instant innovation or no innovation at
all. This is perhaps the characteristic situation
where diffusion must be triggered by macrostructural change. A diffusion theory which accounts for the structural change would explain
such cases fairly well, and would in principle
explain most cases where diffusion either does
not occur in a region or proceeds at an extremely rapid rate. Such a theory would help
us to understand the dynamics of underdevelopment in the modern world, and the cases of
rapid diffusion and nondiffusion which occurred-were
perhaps characteristic of-the
ancient world. It might even help to resolve
some thorny questions of locational origin, since
instant innovation (explosively rapid diffusion)
would be, operationally, very close to independent invention. Is it not indeed possible that
the Old World agricultural revolution took
place everywhere almost at once?
Geography, it seems, is always a step behind
its sister sciences. Our search for hard and
formal theory began at a time when theorybuilding elsewhere was beginning to soften.
Systems models were replacing univariate laws.
Logical positivism was melting into ordinary
language; philosophy of science was beginning
to realize at last that a theory, as product, is
very different from theory-building, as a process; that the steps of reasoning within a theoretical structure do not correspond to the steps
by which, historically, a theory is attained.12
This last discovery has an important implication. Theory-building does not usually begin
with a statement of axioms, but with a much
more modest and difficult endeavor: the uncovering of empirical regularities, the isolation
of variables, the definition of a qualitative system, and thus, in Kniffen’s words, the establishment of “concepts, terms, and usable quantities.”13 This endeavor still is thought of by
12N. R. Hanson, Patterns of Discovery (Cambridge, England: Cambridge University Press, 1958) ;
and Thomas Kuhn, The Structure of Scientific Revolutions (Chicago: University of Chicago Press, 1962).
13Fred B. Kniffen, “Folk Housing: Key to Diffusion,” Annals, Association of American Geographers,
Vol. 55 (1965), p. 577.
September
many geographers as pretheoretical, but the
construction of models is pretheoretical in a
different (and no less meaningful) sense if the
models are built before the minimally necessary
“concepts, terms, and usable quantities” have
been established. If the one is dismissed as
“mere description,” the other must be dismissed
as “empty formalism.” What we seem to need
is a constant dialectical exchange between the
two kinds of theoreticians, the patient conceptualizers and the impatient formalizers. Eventually, this should lead to synthesis and useful
theory.
The need for such an exchange is peculiarly
apparent in diffusion theory. Formal (“spatial”)
diffusion models are weak because their concepts are not very clear, their assumptions about
underlying cultural process are rather shallow,
and their breadth of scope is limited, in general,
to the transitional phase of diffusion in a specific
region. The kind of diffusion theory one finds
in contemporary cultural geography, by contrast, does not display these weaknesses. But it
remains unformalized. Can the strengths of both
be combined?
Conceptual diffusion theory owes as much
to the work of Fred B. Kniffen as formal theory
does to that of Hagerstrand. I need not summarize Kniffen’s work for American geographers, and I need not remind them of its
i m ~ 0 r t a n c e . It
l ~ is useful to call attention here
to certain general principles which emerge from
Kniffen’s work and which bear on the issues
raised in this paper: the need, in diffusion
theory, for clarity, depth, and breadth.
Clarity is in part a question of sharpness in
the definition of variables. Definition is peculiarly sharp if a diffusing culture trait is easily
identified and located, if it occurs in clearly
distinguishable units, and if each occurrence is
relatively permanent, or positionally stable. This
is one reason why Kniffen urges attention to
material settlement forms, like dwellings,
bridges, and fairs. But he is also concerned with
traits of nonmaterial culture (for instance,
spoken language) if trait definition is conceptually and operationally sharp.15 Clarity is also,
14See H. J. Walker and William Haag, eds., Man
and Cultural Heritage: Essays in Honor of Fred B .
Kniffen (Baton Rouge: Louisiana State University
School of Geosciences, 1974).
15Thus Hartshorne quite missed the point of Kniffen’s theoretical approach when he accused him of
1977
VIEWSOF DIFFUSION
in part, a question of sharpness in the recognition of types or categories. Formal theory tends
to rely on diffusing traits for which a simple
presence-or-absence judgment will suffice. Most
diffusion, however, does not involve the addition of new, emergent traits or variables, like
television sets and telephones, but rather the
transformation of existing traits (for example,
the replacement of one kinship system, or one
folk-housing form, or one staple crop, by another). These transformations cannot be modeled until the problem of distinguishing the
different taxonomic forms of a trait has been
resolved; and for this problem, Kniffen’s work
supplies a methodological paradigm.
The lack of depth in formal diffusion theory
is due, as I argue, to the lack of a powerful
theory of the underlying process, a theory of
the forces which propel diffusion. We cannot
simulate a process if our conception of the process itself is unrealistic. Simplification, under
these conditions, is merely caricature. For Kniffen, diffusion is explained and predicted from
the theory of culture; hence culture as a complex
whole, not one or a few of its elements, becomes
the axiom-set for diffusion theory. Of course,
the effect of culture on diffusion is far from
uniform (though far from capricious), and,
since we do not have as yet a general theory for
predicting this effect, we have no general basis
for predicting diffusion. With Kniffen’s approach we at least have a dependable foundation, and we can build upon it.
Lastly, we come to the question of breadth,
the central concern of this paper. Formal
theory, as we saw at the outset, emphasizes
diffusion in a narrow sense: the spread of adoption within a definite region. The process begins
when the trait appears in the region, and not
before. It ends, ordinarily, at the regional
boundaries. In the case of Hagerstrandian diffusion processes, the boundaries are the outer
limits of information-flow and thus cannot be
being overly concerned with material culture. See
Richard Hartshorne, The Nature of Geography (Lancaster, Penna.: Association of American Geographers,
1939), pp. 228-34.
3 49
breached. Diffusion as a general phenomenon
is much larger in space-time breadth, and so
must be diffusion theory. In terms of historical
span, we wish to understand the manner in
which a trait first enters a region, and this demands analysis of the relevant cultural forces,
many of which operate prior to the moment of
initial adoption. In terms of geographic scale,
we wish to understand the way a trait behaves
in an entire system of regions. For these larger
questions, a model of the intraregional transition may be of little help. It often will be useful,
in fact, to model each single transition as an
instantaneous event, and model the overall
process as a boundary-jumping or barriernetwork problem in a cellular system of uniform
regions.16 Here, Kniff en’s approach again provides a firm foundation. For one thing, it is unrestricted as to historical or geographic scope.
For another, it is grounded in the concept of
culture areas-formally
uniform cultural regions assembled into hierarchies of regions, extending from the microgeographic level to the
level of Culture Worlds. Change within a given
culture area is a major research concern for
Kniffen, but there is no a priori preference for
studying one or another pattern of change:
whether a region undergoes a Hagerstrandian
diffusion process or a spatially uniform transition, rapid or slow, will affect the form of the
explanation, but not the nature of the problem.
Change throughout a system of culture areas
(and ultimately throughout the world as a
whole) is of equal or greater concern in Kniffen’s approach, regardless of whether the
change involves a structural transformation in
existing culture areas or a shift in their boundaries.
Hence the scope of diffusion theory in the
Kniff en tradition is diffusion in its broadest,
most adequate sense. If formal models do not
yet exist for this large and complex process,
the basic conceptual theory is nonetheless in
hand.
16 Peter Haggett and Richard Chorley, Network
Analysis in Geography (London: Edward Arnold,
1969), pp. 227-57.