(Structural) Cohesion in Organizations
Douglas R. White
University of California – Irvine
With
James Moody
The Ohio State University
Séminaire " Réseaux et régulation "
Lasmas, IRESCO, Paris, June 2003
Structural Cohesion for Organizations
• Part One – Predictive Cohesion Theory for
Cohesive Blocks and Ridges in Organizations
• Theory and Dynamical Networks; Case Study
Examples using Pajek
– k-ridges of Structural Cohesion (an extension of
Friedkin’s work on cohesion in formal organizations)
– Cohesive Blocks in High School Friendships (w Moody)
– Cohesive Dynamics: the splitting of blocks in
organizations (with Harary)
– Cohesion Dynamics in Biotechnology (with Powell…)
• Part Two – Predictive Cohesion Theory for
Marriage, Class, Community and Ethnicity
Longitudinal Network Studies and Predictive Social Cohesion Theory
D.R. WHITE, University of California Irvine, BCS-9978282
Predictive Social Cohesion Theory
Paper in preparation for MISH, 2004, special issue on Social
Networks, edited by Degenne
• “Traversal” and “structural” cohesion are two graph theoretic
properties of multiconnectivity in networks that are proven by Menger
Theorem (1927) to be isomorphic .
• The isomorphism suggests that multiconnectivity will have strong
predictive effects in networks.
• Organization theory suggests that alternate topologies of
multiconnectivity will vary with types of organizations.
Longitudinal Network Studies and Predictive Social Cohesion Theory
D.R. WHITE, University of California Irvine, BCS-9978282
Predictive Social Cohesion Theory: Basic Measures
Multiconnectivity in networks has two aspects
• Maximum (pairwise, graphwise) “traversal” cohesion
Number of node-independent paths – redundant transmissibility
• Minimum (pairwise, graphwise) “structural” cohesion
Number of nodes in a cutset – resistance to disconnection
Strong predictive effects because by Menger’s Theorem (1927)
• These two multiconnectivity measures are identical
• They are identical both for pairwise and graphwise measures
Longitudinal Network Studies and Predictive Social Cohesion Theory
D.R. WHITE, University of California Irvine, BCS-9978282
Predictive Social Cohesion Theory: graph theoretical distinction for a
graph or a pair of nodes in a graph, following Harary (1969) between:
Multiconnectivity -- the maximum number of node-independent paths
between {each pair; a pair} of nodes in the graph. Following Menger
(1927) it is equivalent to Node connectivity: The minimum number of
nodes whose removal is needed to disconnect the {graph; pair of nodes}.
Multiconnectivity is a measure of cohesion (Harary et al 1965).
Edge connectivity -- the minimum number of edges whose removal is
needed to disconnect the {graph; pair of nodes}. Menger (1927) theorem
was extended by Ford and Fulkerson to the measure of Flow as the
maximum number of edge-independent paths between {each pair; a
pair} of nodes in the graph. Flow is equivalent to edge connectivity and
is not a measure of cohesion (White and Harary 2001).
Longitudinal Network Studies and Predictive Social Cohesion Theory
D.R. WHITE, University of California Irvine, BCS-9978282
Predictive Social Cohesion Theory: BOUNDEDNESS
A k-component of a graph G is a maximal subgraph S with the
following equivalent properties:
connectivity k, the smallest cutset of S is of size k.
multiconnectivity k, the minimal number of node-independent
paths in S connecting pairs of nodes in S is k.
1
4
3
2
5
A k-edge component of a graph is similarly defined using edge
cutsets and edge-independent paths.
Longitudinal Network Studies and Predictive Social Cohesion Theory
D.R. WHITE, University of California Irvine, BCS-9978282
Predictive Social Cohesion Theory -- concerns Node
Connectivity or Multiconnectivity only:
The bow tie graph. The lowest order of graph (n = 5) at
which edge and node connectivities differ (node
connectivity = 1, while edge connectivity = 2). Sets
{1,2,3} and {3,4,5} are cohesive 2-components that
overlap in node 3, while the 2-edge-component
{1,2,3,4,5} is noncohesive. The flow from 1 to 4 is 2, but
the maximum number of node-independent paths is 1.
1
4
3
2
5
Arrows show flows,
which may pass
through the same
intermediate nodes
but must be edgeindependent
Longitudinal Network Studies and Predictive Social Cohesion Theory
D.R. WHITE, University of California Irvine, BCS-9978282
Predictive Social Cohesion Theory: Organizational Structure
Multiconnectivity in networks has two logically possible topologies
•Stacking: component, bicomponent, tricomponent, k-component
•Overlap: at most k-1 nodes in common for k-components
These may occur exclusively or combine in three topologies
•Overlapping hierarchies (k-ridge)
•Pure hierarchical stacking (n-cone)
•Pure overlap of cohesion in its simplest form (bicomponents)
Longitudinal Network Studies and Predictive Social Cohesion Theory
D.R. WHITE, University of California Irvine, BCS-9978282
Predictive Social Cohesion Theory: Organizational Structure
Organization Theory suggests the three typologies have the following
associations
• Pure hierarchical stacking – informal unrestrained cooperative
with decentralized control
• Overlapping hierarchies – constrained by formal organization and
competitive with decentralized control
• Pure overlap of cohesion in its simplest form (bicomponents):
social class, ethnicity and community as formed by intermarriage
and kinship (structural endogamy), auto-reproductive
Longitudinal Network Studies and Predictive Social Cohesion Theory
D.R. WHITE, University of California Irvine, BCS-9978282
Topology 1: Overlapping hierarchies (Abstract Model)
A k-ridge supporting structure is a set of n (k+1)-components that are connected,
with intersections containing at least k nodes, where each (k+1)-component has
node-connectivity greater than k.
A k-ridge structure has connectivity k but supports a series of connected (k+1)components, i.e., of connectivity k.
Figure: 3-ridge structure supporting overlapping 4-components
4
3
4
3
5 3
6
4
4
4
3
3
4
3
4
3
3
3 3
3
5
3
3
3
4
4
3
2003 Douglas R. White, Walter W.
Powell, and Jason Owen-Smith,
Embeddedness in Multiple Networks,
Organization Theory and Structural
Cohesion Theory. In preparation for
Computational and Mathematical
Organization Theory special issue on
Mathematical Representations for the
Analysis of Social Networks within and
between Organizations, guest edited by
Alessandro Lomi and Phillipa Pattison.
Longitudinal Network Studies and Predictive Social Cohesion Theory
D.R. WHITE, University of California Irvine, BCS-9978282
Topology 1: Overlapping hierarchies (Empirical Study 1)
The algorithm for finding social embeddedness in nested
cohesive subgroups is applied to high school friendship
networks (e.g., Fig 2; boundaries of grades are
approximate) and to interlocking corporate directorates.
The usefulness of the measures of cohesion and
embeddedness are tested against outcome variables of
school attachment in the friendship study and similarity
in corporate donations to political parties in the corporate
interlock study. The cohesion variables outperform other
network and attribute variables in predicting the outcome
variables using multiple regression.
Fig 2. Friendship Cohesion in an
American high school
11-12th grade
9th
Nearly identical findings are replicated for school
attachment measures and friendship networks in 12
American high schools from the AddHealth Study
th
(http://www.cpc.unc.edu/addhealth/), Adolescent Risk and 10 grade
Vulnerability: Concepts and Measurement. Baruch
Fischhoff, Elena O. Nightingale, Joah G. Iannotta,
Editors, 2002, The National Academy Press.
2003 James Moody and Douglas R. White, Social Cohesion
and Embeddedness: A Hierarchical Conception of Social
Groups. American Sociological Review 8(1)
8th grade
7th grade
Interpretation: 7th-graders- core/periphery; 8th- two cliques, one hyper-solidary, the other marginalized; 9thcentral transitional; 10th- hang out on margins of seniors; 11th-12th- integrated, but more freedom to marginalize
Longitudinal Network Studies and Predictive Social Cohesion Theory
D.R. WHITE, University of California Irvine, BCS-9978282
Topology 1: Overlapping hierarchies (Empirical Study 2)
ATTACHMENT
INFLUENCE
Source of network diagrams: Friedkin (1998: 156 and 175).
K-ridge model applied
to an example from
Friedkin 1998:
Columbia University
sciences faculty:
cohesive attachments
predict reported flows
of interpersonal
influence
Longitudinal Network Studies and Predictive Social Cohesion Theory
D.R. WHITE, University of California Irvine, BCS-9978282
Overlapping hierarchies (Empirical Study 2)
Prediction from Ridge Attachment to Interpersonal Influence;
Gamma = .714, tau-b = .55, Somer’s D=.5, p < .02.
N=15
Positions
INFLUENCE
Reciprocal
Directional
or
Reciprocal
None
ATTACHMENT
High
Directional
2
1
2
Edge Bridge
only
None
4
2
4
Longitudinal Network Studies and Predictive Social Cohesion Theory
D.R. WHITE, University of California Irvine, BCS-9978282
Topology 2: Stacked hierarchies (Abstract Model)
An n-cone is a stack of k-components for k=1 to n, where each k-component is
nested in a k-1 component.
Each k-component of an n-cone has connectivity k and contains a series of
(k+m)-components for m=1 to n-k.
Figure: An 8-cone supporting nested k-components for k=1 to 8.
3
4
7
8
6
5
Longitudinal Network Studies and Predictive Social Cohesion Theory
D.R. WHITE, University of California Irvine, BCS-9978282
Topology 2: Stacked hierarchies splitting into Overlapping (Study 2)
An operational definition of social cohesion
based on network connectivity measures
cohesiveness as the minimum number k
of actors whose absence would disconnect
a group. Two members of a group with
cohesion level k automatically have at
least k different ways of being connected
through independent paths.
A test of the measure is exemplified by
successful prediction of how a group,
studied longitudinally during a period of
conflict between leaders, divides into two
(Fig 1), based on cohesion and distance.
Fig 1. Snapshot of friendships at successive points in
time in a longitudinal study of friendship in a Karate
club, with leaders labeled T and A and levels of
cohesion coded by color. When members with ties to
both leaders T and A are forced to choose between
them, removing the red lines, two cohesive
hierarchies form that bifurcate the club.
T
A
Reference:
2001 Douglas R. White and Frank Harary,
The Cohesiveness of Blocks in Social
Networks: Node Connectivity and
Conditional Density, vol. 31, no. 1 in
Sociological Methodology 2001: 305-359.
Blackwell Publishers, Inc., Boston, USA.
Connectivity: Blue=4 Red=3
Green=2 Yellow=1
Data source: Wayne Zachary, 1977. An Information Flow Model
for Conflict and Fission in Small Groups. Journal of
Anthropological Research 33:452-73.
T
A
T
T and A start to fight: some must choose sides
members of a
group with
cohesion level
k automatically
have at least k
different ways
of being
connected
through (k)
nodeindependent
paths
A
Opposing cohesive sides emerge
T = karate teacher
A = club administrator
Block Connectivity:
Blue k=4 (quadricomponent)
Red k=3 (tricomponent)
T
A
Green k=2 (bicomponent)
Yellow k=1 (component)
Figure 1a,b,c Data source: Wayne Zachary, 1977. An Information
Flow Model for Conflict and Fission in Small Groups. Journal of
Anthropological Research 33:452-73.
The sides separate along cohesive fracture
Longitudinal Network Studies and Predictive Social Cohesion Theory
D.R. WHITE, University of California Irvine, BCS-9978282
Topology 2: Stacked hierarchies and Dynamics (Empirical Study 2)
Longitudinal Validation of Structural Cohesion Dynamics in Biotechnology
Fig 3. Biotech Collaborations
To account for the development of collaboration among organizations in
the field of biotechnology, four logics of attachment are identified and
tested: accumulative advantage, homophily, follow-the-trend, and
multiconnectivity. We map the network dynamics of the field over the
period 1988-99 (Fig 3 1999). Using multiple novel methods, including
analysis of network degree distributions, network visualizations, and
multi-probability models to estimate dyadic attachments, we
demonstrate how a preference for diversity and multiconnectivity in All ties
1989
choice of collaborative partnerships shapes network evolution.
Cohesion variables outperform scores of other independent variables.
Collaborative strategies pursued by early commercial entrants are
supplanted by strategies influenced more by universities, research
institutes, venture capital, and small firms. As organizations increase
both the number of activities around which they collaborate and the
diversity of organizations with which they are linked, cohesive
New ties
subnetworks form that are characterized by multiple, independent
1989
pathways. These structural components, in turn, condition the choices
and opportunities available to members of a field, thereby reinforcing
an attachment logic based on connection to partners that are diversely
and differently linked. The dual analysis of network and institutional
evolution offers a compelling explanation for the decentralized
structure of this science-based field.
All ties
1989
2003 Walter W. Powell, Douglas R. White, Kenneth W. Koput and Jason
Owen-Smith. Network Dynamics and Field Evolution: The Growth of
Interorganizational Collaboration in the Life Sciences, 1988-99.
And so on
Submitted to: American Journal of Sociology.
to 1999
Longitudinal Network Studies and Predictive Social Cohesion Theory
D.R. WHITE, University of California Irvine, BCS-9978282
Predictive Social Cohesion Theory: Topology 2 (Single
Hierarchy). An article on the biotech industry under
review by Powell, White, Koput and Owen-Smith can
be found at the ~drwhite home page at
http://eclectic.ss.uci.edu/~drwhite/links2pdf.htm
And is reviewed at the Barabási site at
http://www.nd.edu/~networks/linked/newfile18.htm
The rest of this talk will consider Topology 3 (overlap
of bicomponents of structural endogamy for social
class, ethnicity and community as formed by autoreproductive intermarriage and kinship networks.
These slides were prepared with James Moody.
Structural Cohesion for Organizations,
Kinship Networks and Demography
Outline: Part Two
• Introduction: Concepts for Network Cohesion in
Marriage, Class, Community and Ethnicity
• A Network Approach to Marriage Rules and
Strategies via Controlled Demographic Simulation
• Representing Kinship as A Network: P-graphs
• Case Study Examples
– Emergence and Fission of Groups in Social Networks
– Elite and Class Cohesion via Structural Endogamy
– Community/Ethnic Cohesion via Structural Endogamy
Introduction: some questions of interest
1 What is the influence of demography on social structure and the reverse?
2 How does one measure the demography of marriage and network
behaviors in human populations?
3 What is the influence of social structure on such behaviors?
• For this purpose “social structure” is the network of social bonds
among people and with things to which people have significant links
(property, ideas, material and ecological items).
• Some aspects of social institutions are implied or included in this
definition insofar as they are an emergent result of social/legal/political
bonds and of responses to demographic pressures.
Structural demography might include:
• The social field of kinship as the place of (social) reproduction in
which structural endogamies define the reproductive boundaries of
social class, ethnic identities, kinship groups, and so forth.
• The social field of groups, in which cohesion and coordinated social
action emerges within social networks and connectivities define the
limits of cooperation and competition
• The social field of stratification in which groups (or individuals) are
situated (i.e. occupy structural positions) and centralities define
inequalities among individuals and groups within social networks.
The importance of measurement concepts in
structural demography
• Network-based concepts such as structural endogamy,
multiconnectivity, and centrality, when applied to large scale
(community/nation) networks allows the possibility of a social network
approach to questions about:
– longitudinal and historical studies of entire large populations
– social studies on norms and behavior
– studies of the relation between the structural positions of
individuals and their behavior
– relationships between social structure and demographic variables
Applications of Structural Cohesion
• Emergence and Fission of Groups in Social Networks
• Elite and Class Cohesion
• Community/Ethnic Cohesion
– “The Cohesiveness of Blocks in Social Networks: Node
Connectivity and Conditional Density” (drw and Frank Harary).
2001. Sociological Methodology 2001, vol. 31, no. 1, pp. 305-359
– “Social Cohesion and Embeddedness: A hierarchical conception of
social groups” (Moody and White). 2003. American Sociological
Review 68(1):101-24.
Controlled Demographic Simulation: A Network
Approach to Discovering Marriage Rules and Strategies
• In a quantitative science of social structure that
includes marriage and kinship, how does one:
 define and evaluate marriage strategies relative to random
baselines?
 separate ‘randomizing’ strategy from ‘preferential’ strategy?
 detect atomistic strategies (partial, selective) as well as global
or “elementary” marriage-rules or strategies?
“Controlled Simulation of Marriage Systems,” 1999. Journal
of Artificial Societies and Social Simulation 3(2). White
A Network Approach to Marriage Rules and
Strategies via Controlled Demographic Simulation
Categorical attribute models for marriage mixing are problematic, due to ambiguities in the
categories and questions about how to nest various attributes.
A relational approach builds random baselines by comparing against randomized elements of
the observed data. This allows one to hold constant many elements of the kinship system (for
example, matrimonial decent), while testing for random mixing in other elements (‘flow’ of
husbands through the system).
Defining the phenomena of endogamy:
• Endogamy is the custom of marrying only within
the limits of a clan or tribe.
• Practical Strategies:
– By categories/attributes:
• suffers from problems of specification error
– By network relinking:
• the generalized phenomena of structural endogamy as blocks
of generalized relinking, (a special case of network cohesion)
with:
 Subblocks of k-relinkings of k families, with g-depth in
generations
 Subblocks of consanguinal (blood) marriage as within-family
relinkings
Data and Representation:
Building Kinship Networks
To analyze large-scale kinship networks, we need a
generalizable graph representation of kinship networks.
Problems:
•Cultural definitions of “kin” lead to cross-cultural
ambiguity
•Forced to pick ‘primary’ relations (marriage, descent)
against ‘implied’ relations (siblings, cousins, etc.) or include
a complete graph with multiple labeling
Data and Representation:
Building Kinship Networks
The traditional representation is a genealogical kinship graph
•Individuals are nodes
•Males and females have different
shapes
•Edges are of two forms:
•Marriage (usually a horizontal,
double line)
•Descent (vertical single line)
•Has a western bias toward individuals
as the key actor
•Not a valid network, since edges
emerge from dyads
•Better solution is the P-graph
Data and Representation:
Building Kinship Networks
P-graphs link pairs of parents (flexible & culturally defined) to their decedents
P-graphs are constructed by:
•Treating couplings as nodes
•Treating individuals as lines
•Usually of different type for
different genders
Data and Representation:
Building Kinship Networks
P-graphs link pairs of parents (flexible & culturally defined) to their decedents
P-graphs can be constructed from
standard genealogical data files
(.GED), using PAJEK and a
number of other programs.
See:http://eclectic.ss.uci.edu/~drwhite
for guides as to web-site
availability with documentation
(& multimedia representations)
Data and Representation:
Relating p-graphs to endogamy
Cycles in p-graphs are direct markers for endogamy, and satisfy the
elementary requirements for theories of kinship-based alliances
(Levi-Strauss (1969, Bourdieu 1976):
Circuits in the p-graph are isomorphic with one or more of:
•Blood Marriages, where two persons of common ancestry
from a new union
•Redoublement d’alliance, where unions linking two coancestral lines are redoubled
•Renchainement, where two or more intermarried co-ancestral
lines are relinked by a new union
Data and Representation:
Relating p-graphs to endogamy
Lot & his
Wives
Male Decent
Female Decent
Same person
(polygamy)
Programs & Availability
PAJEK
 PAJEK reads genealogical datasets (*.ged files) both the usual Ego
format and in Pgraph format, with dotted female lines (p Dots) and
solid male lines.
 PAJEK Network/Partition/Components/Bicomponent computes
structural endogamy
 PAJEK Network/Partition/Depth/Genealogy computes genealogical
depth. This enabled 2D or 3D drawings of kinship networks.
 Manuals for p-graph kinship analysis and discussions of software
programs & multimedia representations are contained in
 1) “Analyzing Large Kinship and Marriage Networks with pgraph and
Pajek,” Social Science Computer Review 17(3):245-274. 1999 Douglas
R. White, Vladimir Batagelj & Andrej Mrvar.
 2) http://eclectic.ss.uci.edu/pgraph
 3) http://vlado.fmf.uni-lj.si/pub/networks/pajek
Programs & Availability
Hypothesis testing
We can use various permutation-based procedures to test the
observed level of endogamy against a data-realistic random
baseline.
The substantive marker for endogamic effectiveness is whether the
level of endogamy is (a) greater than expected by chance given (b)
the genealogical depth of the graph
1997 Structural Endogamy and the graphe de parenté. Mathématique,
Informatique et sciences humaines 137:107-125. Paris: Ecole des Hautes
Etudes en Sciences Sociales
Applications of Structural Endogamy
Social Class
Social class as “a general way of life, a sub-culture, tends to be hereditary
because (a) individuals from the same sub-culture tend to intermarry, and (b)
parents bring up their children to imitate themselves.” (Leach, 1970).
If we were to examine the extent to which particular social class formations
were concomitant with structural endogamy, we would expect that:
•Families involved would know "good families“ and "suitable matches,”
•not all children of the class would be "required" to marry within the
class, but social class inscription would take place through the diffuse
agency of relinking by marriage,
•which could both validate the social standing of the individual and
constitute the diffuse but relinked social unit -- endogamic block -- of
class formation.
Organizational Applications of Structural Endogamy
Social Class: Carinthian Farmers
“Class is rooted in relations to property, but the holding of property
is particularistic, bound by social relations that channel its
inheritance within particular sets of personal biographies, such as
those linked by kinship and marriage. As property flows through a
social network, its biography unfolds as a history of the transfer
from person to person or group to group.” (p.162)
Institutions (such as class), emerge out of the networked actions and
choices devolving in turn in specific and changing historical
context. A duality of persons and property, each linked through the
others, thus characterizes the class system.
Source: 1997 “Class, Property and Structural Endogamy: Visualizing Networked Histories,” Theory and Society 25:161208. Lilyan Brudner and Douglas White
Organizational Applications of Structural Endogamy
Social Class: Carinthian Farmers
Empirical setting: Inheritance of property among families in an Austrian Village
Background: In the Austrian farming valleys of southern Carinthia, the
perpetuation of Slovenian ethnicities and Windisch dialects has been associated
with heirship of farmsteads. Unlike many rural areas (and as predicted by Weber
and others), farms tended to be inherited complete, without the kind of splitting that
fractures classes.
Main hypothesis: That two social classes emerged historically in this village and
have long remained distinct as a product of differential marriage strategies.
•The mechanism for keeping land intact is that a structurally endogamous
farmstead-owner social class emerged from marriages that relinked stem
family or heirship lines that were already intermarried. The relinked couples
inheriting farmsteads recombined primary heirships with secondary quitclaim
land parcels allowing stability in reconstituting “impartible-core” farmsteads.
Source: 1997 “Class, Property and Structural Endogamy: Visualizing Networked Histories,” Theory and Society 25:161208. Lilyan Brudner and Douglas White
Organizational Applications of Structural Endogamy
Social Class: Carinthian Farmers
Data:
•Extensive field work
•Archival: Records of farmstead transfers starting in the 16th century
•Genealogical histories on families collected by Brudner
•Supplemented from data collected by White from gravestones and church
records
Facts about the setting:
•Village population has been (relatively) stable from 1759 – 1961, fluctuating
between 618 (1923) to 720 (1821)
•Most transfers are through inheritance, but the data includes purchases as well.
•Daughters tend to move to their husbands house of residence
•Purchase of farmsteads for sons is common, but rare for daughters
•Daughters tend to bring a land dowry to a marriage
Source: 1997 “Class, Property and Structural Endogamy: Visualizing Networked Histories,” Theory and Society 25:161208. Lilyan Brudner and Douglas White
Organizational Applications of Structural Endogamy
Social Class: Carinthian Farmers
Source: 1997 “Class, Property and Structural Endogamy: Visualizing Networked Histories,” Theory and Society 25:161208. Lilyan Brudner and Douglas White
Organizational Applications of Structural Endogamy
Social Class: Carinthian Farmers
Source: 1997 “Class, Property and Structural Endogamy: Visualizing Networked Histories,” Theory and Society 25:161208. Lilyan Brudner and Douglas White
Organizational Applications of Structural Endogamy
Social Class: Carinthian Farmers
Structural Endogamy w. Ancestors
Generation
1
2
3
4
5
6
Present:
Actual
8*
16*
70*
179
257
318
Simulated
0
0
32
183
273
335
Actual
8*
58*
168
246
308
339
Simulated
0
18
168
255
320
347
Actual
26*
115*
178
243
278
292
Simulated
0
98
194
262
291
310
Back 1 gen:
Back 2 gen:
Source: 1997 “Class, Property and Structural Endogamy: Visualizing Networked Histories,” Theory and Society 25:161208. Lilyan Brudner and Douglas White
Organizational Applications of Structural Endogamy
Social Class: Carinthian Farmers
Source: 1997 “Class, Property and Structural Endogamy: Visualizing Networked Histories,” Theory and Society 25:161208. Lilyan Brudner and Douglas White
Organizational Applications of Structural Endogamy
Elite Structural Endogamy: Rural Javanese Elites
Empirical Setting: Muslim village elites have their own compounds and
extensive landholdings that qualify them for village leadership. They often
marry blood relatives, while commoners do not.
Key questions: Javanese peasant villages are often characterized as a
‘loose’ social structure. Is the blood-marriage endogamy we see among
village elites simply due to the demographic constraints imposed by very
restricted size of the elite group, with the elites and commoners sharing the
same ‘loose’ rules of marriage?
Data: Extensive field work, genealogies and ethnography by Thomas
Schweizer
Organizational Applications of Structural Endogamy
Elite Structural Endogamy: Rural Javanese Elites
•
Results:
• Apparent differences in marriage patterns of elites and commoners
were due to a common cultural practice of status endogamy, which for
elites implied a set of potential mates whose smaller size implied
marriage among blood relatives within a few generations.
• Given a common rule of division of inheritance, closer marital
relinkings among elites facilitated the reconsolidation of wealth within
extended families
• Extended families so constituted operated with a definite set of rules
for the division of productive resources so as to distribute access to
mercantile as well as landed resources.
•
Graphic technique: Nuclear families as the unit of p-graph analysis,
additional arrows for property flows, and extended family as constituted
by marital relinking and the repartitioning of mercantile and properties
resources.
•Source: 1998 “Kinship, Property and Stratification in Rural Java: A Network Analysis” (White and Schweizer). pp. 3658, In, Thomas Schweizer and Douglas White, eds. Kinship, Networks, and Exchange. Cambridge University Press.
Organizational Applications of Structural Endogamy
Social Integration through Marriage Systems: Kandyan Irrigation Farmers in Sri Lanka
Empirical Setting: An immensely detailed network ethnography by Sir
Edmund Leach demonstrates how kinship relations are strategically
constructed through matrimonial alliances that alter the flow of
inheritance of land and water rights by deviating from normal agnatic
(father’s-side) rights to property and emphasizing the secondary rights of
daughters, with expectation that property alienated through marriage will
flow back to the agnatic group through the completion of elaborate
marriage exchanges between the two “sides” of the kindred.
Key question: Is there a hidden order of marital practices that links to the
two-sidedness of kinship terminology and Leach’s earlier findings about
balanced and reciprocated exchanges?
Data: genealogies, inheritances, classifications of normal and exceptional
residence practices and of normal and exceptional types of marriage.
Source: 1998 “Network Mediation of Exchange Structures: Ambilateral Sidedness and Property Flows in Pul Eliya, Sri Lanka”
(Houseman and White). pp. 59-89, In, Thomas Schweizer and drw, eds. Kinship, Networks, and Exchange. CUP.
Organizational Applications of Structural Endogamy
Social Integration through Marriage Systems: Kandyan Irrigation Farmers in Sri Lanka
Results: Reveals that Leach had not seen, and could not for lack of
requisite tools of analysis, that marriages were organized in response to a
logic called dividedness and (in another form) sidedness.
the matrimonial network is bipartite, the marriages of the parents
and those of the children divide themselves into two distinct
ensembles (which have nothing to do with moieties).
•Graphic technique: Nuclear families as the unit of p-graph analysis,
analysis of blood marriages, sibling sets and of inheritance or bequests
revealed the underlying logic of marital sidedness.
•Key concepts: bipartite graph and sidedness: sidedness is an empirical
bipartition of a matrimonial network, reiterated from one generation to
another following a sexual criterion. The next slide the sidedness of the
Pul Eliyan networks operating through the male line, with some female
heirs acting as agnatic channels for inheritance where there are no male
heirs (I.e., they lack brothers).
Source: 1998 “Network Mediation of Exchange Structures: Ambilateral Sidedness and Property Flows in Pul Eliya, Sri Lanka”
(Houseman and White). pp. 59-89, In, Thomas Schweizer and drw, eds. Kinship, Networks, and Exchange. CUP.
P-graph of Pul Eliyan Sidedness
P-graph of Pul Eliyan Sidedness and Property Transactions
Curved lines follow
property flows, dashed
lines are gifts.
Property re-connects
across the sided lines.
Correlating Actual versus Simulated non-MBD marriages
for Pul Eliya, showing tendency towards a Viri-Sided
(Dravidian) Marriage Rule
Viri-Sided
Actual
18
Simulated
5
Unsided
0
7
(p=.0004; p=.000004 using the binomial test of 50%:50%
expected)
Source: 1998 “Network Mediation of Exchange Structures: Ambilateral Sidedness and Property Flows in Pul Eliya, Sri Lanka”
(Houseman and White). pp. 59-89, In, Thomas Schweizer and drw, eds. Kinship, Networks, and Exchange. CUP.
Correlating Balanced vs. Unbalanced Cycles in Actual
versus Simulated marriage networks for Pul Eliya,
showing a perfectly Sided (Dravidian) Marriage Rule
A. Viri-sidedness
Actual
Expected
Balanced Cycles (Even length) 25
17.5
Unbalanced Cycles (Odd Length) 10
17.5
p=.008
(all exceptions involve relinkings between nonconsanguineal relatives)
B. Amblilateral-sidedness
(women‘s sidedness adjusted by inheritance rules)
Actual
Balanced Cycles (Even length) 35
Unbalanced Cycles (Odd Length) 0
p=.00000000003
Expected
17.5
17.5
Source: 1998 “Network Mediation of Exchange Structures: Ambilateral Sidedness and Property Flows in Pul Eliya, Sri Lanka”
(Houseman and White). pp. 59-89, In, Thomas Schweizer and drw, eds. Kinship, Networks, and Exchange. CUP.
Organizational Applications of Structural Endogamy
A Turkish Nomadic Clan as prototype of Middle Eastern segmented lineage systems:
The Role of Marital Cohesion
Empirical Setting: An Arabized nomadic clan having the characteristic segmented
patrilineages, lineage endogamy, and FBD (father’s brother’s daughter) marriages
Key questions: Is this a prototype of a widespread variety of decentralized
self-organizing lineage system stemming Arab societies or societies Arabized
along with the spread of Islam in 7th and 8th century?
Data: Genealogies on two thousand clan members and their ancestors, from
1800 to the present, a long-term ethnography by Professor Ulla C. Johansen,
University of Cologne
Organizational Applications of Structural Endogamy
A Turkish Nomadic Clan as prototype of Middle Eastern segmented lineage systems:
The Role of Marital Cohesion
Sources:
2002 Ulla Johansen and Douglas R. White, Collaborative Long-Term Ethnography
And Longitudinal Social Analysis of a Nomadic Clan In Southeastern Turkey, pp. 8199, Chronicling Cultures: Long-Term Field Research in Anthropology, eds. R. van
Kemper and A. Royce. AltaMira Press.
2003 Douglas R. White and Michael Houseman The Navigability of Strong Ties: Small
Worlds, Tie Strength and Network Topology, Complexity 8(1).
2003 Douglas R. White and Ulla Johansen. Network Analysis and Ethnographic
Problems: Process Models of a Turkish Nomad Clan. Lexington and AltaMira. In
Press.
Organizational Applications of Structural Endogamy
A Turkish Nomadic Clan as prototype of Middle Eastern segmented lineage systems:
The Role of Marital Cohesion
Generations
Data:
p-graph of the conicality of the nomad clan
Organizational Applications of Structural Endogamy
A Turkish Nomadic Clan as prototype of Middle Eastern segmented lineage systems:
The Role of Marital Cohesion
Results:
•The index of relinking of a
kinship graph is a measure of
the extent to which marriages
take place among descendents
of a limited set of ancestors.
• For the nomad clan the index
of relinking is 75%, which is
extremely high by world
standards.
•This is a picture of the
structurally endogamous or
relinked marriages within the
nomad clan (nearly 75% or all
marriages):
Structural Endogamy of the nomad clan
Organizational Applications of Structural Endogamy
A Turkish Nomadic Clan as prototype of Middle Eastern segmented lineage systems:
The Role of Marital Cohesion
Does staying together as a clan depend on marital relinking?
Results: Testing the hypothesis for stayers versus leavers
Relinked
Marriages
Non-Relinking
Marriages
Totals
villagers who became clan members
2**
1**
clan Husband and Wife
148
0
“ Hu married to tribes with reciprocal exchange 12
14
“ Hu left for village life
13
23
“ Hu married to village wife (34) or husband (1) 11
24
“ Hu married to tribes w/out reciprocal exchange 2
12
“ members who left for another tribe
0
8
villagers not joined to clan
1
3**
* tribes
**non-clan by origin
Totals
189
85
Pearson’s coefficient r=.95 without middle cells
3
148
26
36
35
5
8
4
274
Organizational Applications of Structural Endogamy
A Turkish Nomadic Clan as prototype of Middle Eastern segmented lineage systems:
The Role of Marital Cohesion
Results: Rather than treat types of marriage one by one: FBD, MBD etc., we
treat them as an ensemble and plot their frequency distribution
A power-law decay of marriage frequencies with kinship distance
180
160
140
M
Frequency
M =206/x
0 + 156/x^2
2
120
# of Types
100
(power law preferential curve)
80
60
# of Couples
40
FFZSD FFBSD:10-11 FZD:14 MBD:16
FBD:31
20
0
0
Raw
5 frequency 10
15
20
25
Organizational Applications of Structural Endogamy
A Turkish Nomadic Clan as prototype of Middle Eastern segmented lineage systems:
The Role of Marital Cohesion
Results:
reversing axes, types of
marriage are ranked here
to show that
numbers of blood
marriages follow a
power-law (indexical
of self-organizing
preferential
attachments)
while affinal relinking
frequencies follow an
exponential distribution
Organizational Applications of Structural Endogamy
A Turkish Nomadic Clan as prototype of Middle Eastern segmented lineage systems:
The Role of Marital Cohesion
Results: Does the high degree of structural endogamy create a single root to the
nomadic clan?
An apical (circled)
ancestor of the 90%
of those down to
today’s nomad clan
members.
Attributing common
unilineal descent because
of common roots is a
common feature of
Middle Eastern lineages
Organizational Applications of Structural Endogamy
A Turkish Nomadic Clan as prototype of Middle Eastern segmented lineage systems:
The Role of Marital Cohesion
Results: Summary:
– Who stays and who returns to village life is predicted from kinship
bicomponent membership.
– Bicomponent relinking also plays a role in the emergence of a root ancestor,
and of more localized root ancestors for different levels of kinship groupings.
– Dynamic reconfigurations of political factions and their leaders are predicted
from ensembles with different levels of edge-independent connectivity.
– An index of the decline of cohesion of the clan would be the fragmentation of
cohesive components in later generations...
•
•
•
Key concepts: bicomponent, edge-independent paths, connectivity.
Graphic technique: nuclear families as the unit of p-graph analysis.
An explanation of methods will be found in a book ms. : Social Dynamics of a
Nomadic Clan in Southeastern Turkey: An Introduction to Networked Histories.
Douglas White and Ulla Johansen. For submission to Westview or Altamira Press.
Conclusion?
• Predictive Cohesion Theory has broad
applications and empirical support in a
variety of studies
Bibliography:
Brudner and White. 1997 “Class, Property and Structural Endogamy: Visualizing Networked
Histories,” Theory and Society 25:161-208.
Houseman and White. 1998 “Network Mediation of Exchange Structures: Ambilateral Sidedness and
Property Flows in Pul Eliya, Sri Lanka” pp. 59-89, In, Thomas Schweizer and drw, eds. Kinship,
Networks, and Exchange. CUP.
Moody and White. 2003. “Social Cohesion and Embeddedness: A hierarchical conception of social
groups” American Sociological Review 68:101-24.
White. 1997. “Structural Endogamy and the graphe de parenté” Mathématique, Informatique et sciences
humaines 137:107-125.
White. 1999. “Controlled Simulation of Marriage Systems” Journal of Artificial Societies and Social
Simulation 3(2).
White, Batagelj and Mrvar. 1999. “Analyzing Large Kinship and Marriage Networks with pgraph and
Pajek,” Social Science Computer Review 17:245-274.
White and Harary. 2001. “The Cohesiveness of Blocks in Social Networks: Node Connectivity and
Conditional Density” Sociological Methodology 31:305-359
White and Jorion. 1996. “Kinship Networks and Discrete Structure Theory: Applications and
Implications.” Social Networks 18:267-314
White and Schweizer 1998. “Kinship, Property and Stratification in Rural Java: A Network Analysis”
pp. 36-58, In, Thomas Schweizer and Douglas White, eds. Kinship, Networks, and Exchange. Cambridge
University Press.
Longitudinal Network Studies and Predictive Social Cohesion Theory
D.R. WHITE, University of California Irvine, BCS-9978282
Predictive Social Cohesion Theory
Summary and Extensions
Where would the concept of structural endogamy connect to current population
concerns?
Social reproduction of ethnicity through differential fertility
Differences in reproductive rates by social groups mean that
genealogical distance is shorter in some groups than others, likely
implying very different relinking patterns.
For example, if one race/ethnic group tends to (a) couple younger, (b) have
children younger, and/or (c) re-marry/couple more often than another
race/ethnic group, then social divisions between those groups will likely
expand, and we would likely see a stronger social reproduction of class
within the more strongly re-linked group.
Current (historical) work w. Padgett on Florentine families (N~98,000) works
through some of these ideas.
Summary and Extensions
Where would the concept of structural endogamy connect to current population
concerns?
Ethnic Intermarriage and the identification of ethnicity
There is a direct link between questions of structural endogamy and intergroup marriage, that is ripe for an extension.
•Classical models in this area fit log-linear models to husband_race by
wife_race mixing tables. We can broaden our view of inter-mixing, by
tracking the salience of race/ethnicity as the degree to which race and
ethnicity reflect real communities through re-linking.
•If ethnically-based endogamy decreases over time, for example, then
we can argue for a decreasing salience of that ethnicity.
•Looking forward, the re-linked community of today can become the
ethnicity of tomorrow in a processual sense
•An interesting extension will be to the demarcations between
ethnicities within relinked communities. Is the pattern really one of
total group mixing, or is contact at the peripheries of communities?
Summary and Extensions (from paa talk)
Where would the concept of structural endogamy connect to current population
concerns?
Class Mobility
We can make a similar line of argument for national/ regional elite
structures.
Historically, white elites sent their children to a very small subset of all
schools (boarding and college), where they mixed within a very small set of
potential marriage partners.
•This would emerge as an endogamous class of elites (We can show, for
example, that almost all US Presidents can be relinked to a common
elite US ancestor).
• If recent attempts at affirmative action and universal education have
been successful, then we would expect greater out-marriage and lower
re-linking