Transcript No Slide Title

Kinship Networks and Demography
Douglas R. White
University of California – Irvine
With
James Moody
The Ohio State University
Population Association of America
Minneapolis Minnesota, May 1 - 3
Kinship Networks and Demography
Outline
• Introduction: Social Demography and Network
Concepts
• A Network Approach to Marriage Rules and
Strategies via Controlled Demographic Simulation
• Representing Kinship as A Network: P-graphs
• Case Study Examples
• Possible Extensions
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
• 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
Example: Analyzing cohesion in social groups
(Cohesive Blocking):
• Cohesion is measured by the number of node-independent paths that hold two nodes
together. Two nodes with k node-independent paths are k times as resistant to being pulled
apart than if they are connected by a single path.
• A k-component of a graph, or a maximal subgraph that is k-connected (also called a
cohesive block of connectivity k), is a maximal subgraph S in which no pair of nodes can be
disconnected by removal of k or fewer other nodes in S. The 1-, 2-, and 3-components of a
graph G are called, respectively, components, bicomponents and tricomponents of G.
• Menger’s Theorem: The minimum node cut set (connectivity) of a graph G equals the
minimum of the maximum node-independent paths (cohesion) between any two nodes in G.
This is one of the deepest theorems in graph theory.
• If the edges of a graph (network) are weighted (e.g., at unity), the node-independent flow
between two nodes is the sum over node-independent paths of minimum weights on these
paths.
E.g., node-independent flow of 2 between a & b:
a
b
(the graph is 2-connected)
Cohesion via multiple independent paths
•
The cohesion of a graph G is independent of path distances between nodes, and is in this
sense a distributed property of G.
•
Why do we expect that multiple independent paths, independent of distances among
nodes, will have important effects above and beyond proximal and highly distancedependant effects of interaction?
–
Briefly, independent of distance: (a) Two nodes with k node-independent paths are k times as
resistant to being pulled apart than if they are connected by a single path, and (b) The effects
of k node-independent paths within cohesive blocks are convergent and their effects may
thus be self reinforcing. The higher the connectivity k, the more cohesive blocks are
redundantly connected (solidary) in this way, and the greater their potential to act as amplifiers
for coherent patterns of organization.
•
This concept is useful for generating hypotheses relating to social networks generally
and to kinship networks in particular.
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
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 to 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.
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 networks 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
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: The 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 making from some 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
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
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
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
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
Applications of Structural Endogamy
Social Class
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
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, 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 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
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.
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
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.
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 that the authors call dividedness and in another
form sidedness: invisible to the untrained eye, 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 -- 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
Jim – you could scan page 70 of the
book I sent you if it would help
The slide that follows shows how
sidedness was discovered by controlled
simulation methods
Frequencies of Actual versus Simulated Consanguineal Marriages for Pul Eliya,
Sri Lanka. Conclusions: All blood marriages are patri-sided, and secondarily, only
MBD is a marriage that is especially preferred
Type
Actual Simul
of Mar. Freq. Freq.
Total
Total Fisher|-----Blood Marriage------|
Actual Simul Exact
type
P-graph notation
12:
5
0
40
38 p=.042 MBD(1)GF=FG
2:
1:
3:
4:
5:
6:
7:
8:
9:
10:
11:
13:
14:
15:
16:
17:
18:
19:
20:
21:
22:
23:
24:
25:
26:
3
0
0
1
0
1
0
2
0
0
0
0
1
1
1
1
1
1
1
1
1
1
0
0
1
1
1
1
0
1
0
1
1
1
1
1
1
0
0
0
0
0
0
0
0
0
0
1
1
0
39
56
6
3
5
18
17
18
9
4
6
25
14
7
8
8
9
3
8
3
13
15
11
11
11
40
57
6
1
3
15
12
12
5
5
3
27
10
3
4
2
3
0
2
0
8
13
5
5
4
.317
.508
.538
.800
.444
.558
.433
.661
.399
.600
.400
.528
.600
.727
.692
.818
.769
1.000
.818
1.000
.636
.551
.352
.352
.749
FZD
FZ
FFFZDSD
FFMZDSSD
FFMBDSDD
FMBSD
FMBDD
FMZDD
FMMBSSD
FMMFZSSD
FMMFZDSD
MBSD
MFZDD
MFFZDSSD
MFFZDSD
MFMBDSSD
MFMBDD
MFMBDDDD
MFMFZSSD
MFMFZDDD
MMZSSD
MMBDD
MMZSDD
MMBDDD
MMZDDD
GG=FF
GG=F
GGGG=FGFF
GGGF=FGGFF
GGGF=FFGFG
GGF=FGG
GGF=FFG
GGF=FFF
GGFF=FGGG
GGFFG=FGGF
GGFFG=FGFF
GF=FGG
GFG=FFF
GFGG=FGGFF
GFGG=FGFF
GFGF=FGGFG
GFGF=FFG
GFGF=FFFFG
GFGFG=FGGF
GFGFG=FFFF
GFF=FGGF
GFF=FFG
GFF=FFGF
GFF=FFFG
GFF=FFFF
(2)Viri-Sided?
Actual
Simul
yes
yes
no
no
yes
no
yes
no
yes
no
yes
yes
yes
yes
yes
yes
yes
yes
yes
yes
yes
yes
yes
no
no
yes
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 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.
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 Caliphates the societies?
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
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.
the next slide is produced as a Pajek image putting generations
into the vertical axis and scaling cohesion on the horizontal plane
of the figure (smaller nodes are receeding on the horizon)
Applications of Structural Endogamy
A Turkish Nomadic Clan as prototype of Middle Eastern segmented lineage systems:
The Role of Marital Cohesion
Data:
p-graph of the conicality of the nomad clan
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 measure of the
extent to which marriages take
place among descendents of a
limited set of ancestors. For the
nomad clan genealogies 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
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
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
Applications of Structural Endogamy
A Turkish Nomadic Clan as prototype of Middle Eastern segmented lineage systems:
The Role of Marital Cohesion
Results:
100
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)
turk cons
# of
Couples
turk relink2
Log. (turk relink2)
Power (turk cons)
10
while affinal relinking
frequencies follow an
exponential distribution
Ranking of Types
1
1
10
100
1000
10000
100000
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
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.
Applications of Structural Endogamy
A Turkish Nomadic Clan as prototype of Middle Eastern segmented lineage systems:
The Role of Marital Cohesion
Key questions (based on Ula Johansen’s ethnography)
1. Was there a single genealogical root to the nomadic clan?
2. How are kinship units form and why do units of different scale bear the same nam
• aile for family, minimal lineages and larger joint families
• kabile for tribes or smaller lineages
3. How and why is kinship the result of marriages?
Basic hypothesis:
To the extent that marriages relink different families, patterns of “structural
endogamy” defined by relinking reinforce and redefine the effective
units and subunits formed by consanguineal kinship links among
families.
Applications of Structural Endogamy
A Turkish Nomadic Clan as prototype of Middle Eastern segmented lineage systems:
The Role of Marital Cohesion
Results: Was there a single root to the nomadic clan?
• The number of descendants of each ancestor is a simple genealogical
calculation from the p-graph.
• It turns out that there is one single apical ancestor for 90% of clan
between generations 3 and today’s clan members.
• This occurs because descendants of the “root” ancestor relink with
others, so nearly everyone becomes a descendant of the root, and
because those who do not relink tend to leave the clan.
• The “root” ancestor occurs at the generation where a single effective
“matchmaker” effectively relinks all the sibling sets in the clan through
the marriages of his children, one of them becomes the “root.”
Applications of Structural Endogamy
A Turkish Nomadic Clan as prototype of Middle Eastern segmented lineage systems:
The Role of Marital Cohesion
Results: Did all 1000+ clan members follow Qur’anic rules of samegeneration marriage? Whyso?
•
Individuals may be blood-related in several different ways. Doesn’t that lead
to ambiguity in defining “same generation”?
•
The “generation” of each marriage is determined in a p-graph by minimizing
the number of generations needed to keep parents and children at distinct
generational levels.
•
By this criterion, same generation marriages account for 79% of all marriages,
and one-generation differences account for 17% (96% total, even up to sixth
cousins). Up to 2nd cousins, 92% of blood marriages are same generation.
•
Consistent with the importance of establishing cohesion at multiple levels
through marriage, same-generation marriages minimize competition
between generations over mates.
Applications of Structural Endogamy
A Turkish Nomadic Clan as prototype of Middle Eastern segmented lineage systems:
The Role of Marital Cohesion
Results: How did leaders emerge out of the background of followers in
their lineage and their clan?
•
Tanidik kisiler (=known persons) emerge as leaders partly by force of their
personality, but also by the extent of their support network not only from their
lineage, but in support that is distributed across lineages.
•
Hence the hypothesis that “distributed cohesion” is a basis for sets of people
who are the support group for competing leaders has two aspects:
– such groups overlap, criss-cross, and may contain structural “holes,” but
are stronger to the extent that they span larger segments of the entire clan,
and do not consist of just a localized and partial faction
– the level of cohesion can be measured by the number of edge-independent
paths between pairs within the group, including the leader. This is
equivalent to the maximum flow capacity for between each pair, where a
single parent-child link is considered to have a capacity of unity. This
measure can be computed in UCINet.
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.
4. Dynamical Analysis of Longitudinal
Network Data: Pajek
• Vector (*.vec) is a Pajek object with a format similar to
partitions, except that values can be real numbers (not only
positive integers)
– Editing vectors and making vectors from partition and vector
transformations (multiplying by a constant, absolute, sqrt,
normalizations).
– Reordering and binary operations on vectors (sum, difference,
product, division, min, max) and additional operations according to
neighbors.
– Retrieving and putting coordinates of network to vector and vice
versa.
• demographic vectors are produced as a result of reading
GEDCOM files added (birth, marriage, death dates, etc.)
4. Dynamical Analysis of Longitudinal
Network Data: Pajek
• Network/Generate in Time and Options/Previous/Next produce time
series graphics that take vectors into account through node size.
– implemented File/TimeEventsNetwork/Read and /Save for reading and
saving a time network in time events format
– Draw-Vector and Draw-Partition-Vector (sizes of vertices are
determined by selected vector).
– Options/Layout/Arrows in the Middle for drawing arrows in the middle
of lines added.
• Export to Scalable Vector Graphics (SVG) format for *.html or web
presentations and Exports to SVG format using partition. SVG has
incredibly good resolution for printing as well as web presentation and
allows ASCII editing of the print files to tune line width, colors, nodes,
labels, etc.
Extensions of Structural Endogamy
Dynamic Analyses
The p-graph format allows for direct analyses of structural
change, based on real and genealogical conceptions of time.
PAJEK, for example, can create measures on time-defined slices
of the total network.
•Example: High betweenness centrality occurs in the case of Turkish Nomads
not for clan leaders but
–in the early generations, for clan and lineage founders who later become
“marriage makers” whose descendants intermarry or relink with other lineages.
Hence they lose their centrality after the intial “founder” phase.
–in the later generations, for the ancestors of family units that break up and do
not intermarry or relink with other lineages.
Extensions of Structural Endogamy
Demographic Processes
Relationships between network variables and classical
demographic indicators -- fertility, migration, nuptiality and
age of marriage, mortality, etc . -- can be studied when the
quality of the database permits..