Data from: The network motif architecture of dominance hierarchies

The widespread existence of dominance hierarchies has been a central
puzzle in social evolution, yet we lack a framework for synthesizing the
vast empirical data on hierarchy structure in animal groups. We applied
network motif analysis to compare the structures of dominance networks
from data published over the past 80 years. Overall patterns of dominance
relations, including some aspects of non-interactions, were strikingly
similar across disparate group types. For example, nearly all groups
exhibited high frequencies of transitive triads, whereas cycles were very
rare. Moreover, pass-along triads were rare, and double-dominant triads
were common in most groups. These patterns did not vary in any systematic
way across taxa, study settings (captive or wild) or group size. Two
factors significantly affected network motif structure: the proportion of
dyads that were observed to interact and the interaction rates of the
top-ranked individuals. Thus, study design (i.e. how many interactions
were observed) and the behaviour of key individuals in the group could
explain much of the variations we see in social hierarchies across
animals. Our findings confirm the ubiquity of dominance hierarchies across
all animal systems, and demonstrate that network analysis provides new
avenues for comparative analyses of social hierarchies.