Geoscience Reference
In-Depth Information
toward the environment, and are often important in understanding a previous
or subsequent interaction with individuals. Interactions (A attacks B) are hard
to interpret without records of actions (A accidentally drops fruit, B picks up
fruit).
Above action and interaction in the hierarchy of social dynamics are social
relationships. Relationships are quantified by the rates, frequencies, and pat-
terning of component interactions and may be described in terms of the diver-
sity of interactions, the degree of reciprocity or complementarity, relative fre-
quency and pattern of interactions, synchronicity, and multidimensional
qualities. In principle, relationships may be stationary or transitionary. The
former do not change with prior experience (intrinsic development) or condi-
tions (extrinsic modification) and are at most rare and perhaps nonexistent in
mammalian societies. Generalizations about relationships can be sought in
various ways. Dyads may be assigned to predefined categories such as age, sex,
kinship, or even personality (Faver et al. 1986). Personality, in this context, is
a consistent moderator of interactions; for example, a shy animal tends to act
differently from a bold animal under the same circumstances (Stevenson-
Hinde 1983). Block model methods allow subgroupings to be isolated from
sociomatrices. For example, Iacobucci (1990) compared 13 methods for
recovering subgroup structure from dyadic interaction data. In general, block
models are based on structural equivalence of sociomatrices (see “Analysis of
Observational Data”). Some individuals behave similarly in respect to their
age, status, or sex. Using block models, these relationships between individu-
als can be extracted and further studied, for example, using tests for reciproc-
ity and interchange of behaviors (Hemelrijk and Ek 1991) or using more
detailed methods based on time structure of the processes (Haccou and Meelis
1992). In their study of capybara mating systems, for example, Herrera and
Macdonald (1993) disentangled the effects of dominance on mating success.
In that example, dominant males secured more matings than any other indi-
vidual, but fewer matings than subordinate males as a class; this arose because
while the dominant was busy driving off one subordinate, another sought
quickly to mate with the female.
SOCIAL NETWORKS
The sum of social relationships may be compiled in a matrix of dyadic inter-
actions to produce a social network (Pearl and Schulman 1983). Analysis of
sociomatrices assumes stationarity, which, as we have noted, is effectively non-
existent. The solution is to divide sociomatrices into appropriately defined
