kinship networks and demography

Kinship Networks and Demography

Douglas R. WhiteUniversity of California – Irvine

With

James MoodyThe Ohio State University

Population Association of AmericaMinneapolis Minnesota, May 1 – 3, 2003

Anthropological Sciences ColloquiumStanford University, Nov 14, 2003

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

• Current and Possible Extensions

Introduction: some questions of interest1 What is the influence of demography on social structure and the reverse?

More generally, of localized network behaviors on social organization & structure operating through micro-macro network linkages?

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 and Fields in Social Networks – “Network Dynamics and Field Evolution: The Growth of Interorganizational

Collaboration in the Life Sciences.” (Walter W. Powell, drw, Kenneth W. Koput and Jason Owen-Smith). Forthcoming 2004: American Journal of Sociology

• 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.

• Elite and Class Cohesion– “Class, Property and Structural Endogamy: Visualizing Networked Histories,”

(Lilyan Brudner and drw) 1997. Theory and Society 25:161-208.

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 marriage within the limits of a clan, class,

caste, etc., with relative degrees of closure.

• 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


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


P-graphs link pairs of parents (flexible & culturally defined) to their decedents

P-graphs are constructed by:

•Treating individuals as lines

•Usually of different type for different genders

•Treating couplings as nodes


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 co-ancestral lines are redoubled•Renchainement, where two or more intermarried co-ancestral lines are relinked by a new union

•These can be subsumed as subtypes of marital relinking

Data and Representation:Relating p-graphs to endogamy

Male Decent

Female Decent

Same person (polygamy)

Lot & his Wives

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 in a p-graph

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 4) forthcoming book by de Nooy, Batagelj and Mrvar

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 EndogamySocial 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 EndogamySocial Class: Carinthian Farmers

Source: 1997 “Class, Property and Structural Endogamy: Visualizing Networked Histories,” Theory and Society 25:161-208. Lilyan Brudner and Douglas White

“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.


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.


Applications of Structural EndogamySocial Class: Carinthian FarmersData:

•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


Structural Endogamy w. AncestorsGeneration 1 2 3 4 5 6Present:Actual 8* 16* 70* 179 257 318Simulated 0 0 32 183 273 335Back 1 gen:Actual 8* 58* 168 246 308 339Simulated 0 18 168 255 320 347Back 2 gen:Actual 26* 115* 178 243 278 292Simulated 0 98 194 262 291 310



Applications of Structural EndogamyElite 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

Applications of Structural EndogamyElite 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. 36-58, In, Thomas Schweizer and Douglas White, eds. Kinship, Networks, and Exchange. Cambridge University Press.

Applications of Structural EndogamySocial 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.

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 shows sidedness in 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) and they marry outsiders from distant villages.

Applications of Structural EndogamySocial Integration through Marriage Systems: Kandyan Irrigation Farmers in Sri Lanka


P-graph of Pul Eliyan Sidedness

P-graph of Pul Eliyan Sidedness

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 Unsided

Actual 18 0Simulated 5 7

(p=.0004; p=.000004 using the binomial test of 50%:50% expected)


Correlating Balanced vs. Unbalanced Cycles in Actual versus Simulated marriage networks for Pul Eliya, showing a perfectly Sided (Dravidian) Marriage Rule

A. Viri-sidednessActual Expected

Balanced Cycles (Even length) 25 17.5Unbalanced 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 ExpectedBalanced Cycles (Even length) 35 17.5Unbalanced Cycles (Odd Length) 0 17.5

p=.00000000003


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 segmentedpatrilineages, 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

Applications of Structural EndogamyA Turkish Nomadic Clan as prototype of Middle Eastern segmented lineage systems:


Sources: 2002 Ulla Johansen and Douglas R. White, Collaborative Long-Term Ethnography and Longitudinal Social Analysis of a Nomadic Clan In Southeastern Turkey, pp. 81-99, 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.

p-graph of the conicality of the nomad clan



Data:

Gen

erat

ions

•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):


The Role of Marital CohesionResults: Structural Endogamy of the nomad clan



Does staying together as a clan depend on marital relinking?Results: Testing the hypothesis for stayers versus leavers

Relinked Non-Relinking Marriages Marriages Totals villagers who became clan members 2** 1** 3 clan Husband and Wife 148 0 148 “ Hu married to tribes with reciprocal exchange 12 14 26 “ Hu left for village life 13 23 36 “ Hu married to village wife (34) or husband (1) 11 24 35 “ Hu married to tribes w/out reciprocal exchange 2 12 5 “ members who left for another tribe 0 8 8 villagers not joined to clan 1 3** 4

* tribes **non-clan by origin Totals 189 85 274

Pearson’s coefficient r=.95 without middle cells

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



Results: Does the high degree of structural endogamy create a single root to the nomadic clan?



A power-law decay of marriage frequencies with kinship distance

020

4060

80100

120140

160180

0 5 10 15 20 25

Frequency0 + 156/x 2̂

FFZSD FFBSD:10-11 FZD:14 MBD:16 FBD:31

MM =206/x2

Raw frequency

(power law preferential curve)

# of Couples

# of Types

Results: Rather than treat types of marriage one by one: FBD, MBD etc., we treat them as an ensemble and plot their frequency distribution



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

– 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. Submitted: Lexington and Altamira Press.


The Role of Marital CohesionResults: Summary:

– The frequency distributions of different kinds of affinal relinkings were tested in two societies, and a separate test was done for consanguineal relinkings.

– The societies with high rates of blood marriages had preferential attachment power-law distributions for different types of consanguineal relinkings, but exponential decay distributions for different types of affinal relinkings

– Most societies with low rates of blood marriage had exactly the reverse.

– The approach was generalized to the study of short-cycle frequencies in any kind of network with multiple types or nodes and/or edges.

• Key concepts: power-law, exponential rank frequency distributions. • Graphic theoretic techniques: independent cycle theorem, cycle generation concept • 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. Submitted: Lexington and Altamira Press.

Links to Complexity TheoryOut of the Turkish Nomad study came hypotheses about preferential attachments

Ring Cohesion Theory Results: Summary:

Summary and ExtensionsWhere 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.

Historical work w. Padgett reconstructing Florentine elite marriage and kinship nentworks (N~98,000) works through some of these ideas.

There is a direct link between questions of structural endogamy and inter-group 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?


Ethnic Intermarriage and the identification of ethnicity

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, extending the work of Gary Boyd Roberts, that most US Presidents are relinked through common elite US ancestors).

• If recent attempts at affirmative action and universal education have been successful, then we would expect greater out-marriage and lower re-linking


Class Mobility

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.

kinship networks and demography

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