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other simultaneously until one individual defects. The other will then retaliate
to this defection, typically in less than half a second, by terminating allo-
grooming. No elaborate scorekeeping or partner recognition is required to
guard against cheating in this cooperative system. (see figure 10.3a).
We hypothesize that the bartering of allogrooming is so direct because in
the putatively primitive society of the badger, individuals spend most of their
waking hours foraging separately from one another (Kruuk 1978). As a conse-
quence, there are few opportunities to pay back beneficence in other curren-
cies such as coalitionary aid. Perhaps more importantly, there are also few
opportunities for badgers to exert manipulative pressure and extort grooming
from other individuals by threat of negative reciprocity. An exception may
help prove the rule: During the breeding season, when larger badgers can
despotically control breeding opportunities around the sett, smaller individu-
als sometimes abandoned the “You scratch my back, I'll scratch yours” strategy
and groomed larger individuals even without reciprocation (figure 10.3c). The
only other exception to the direct reciprocation rule was found when mothers
groomed cubs that were too young to reciprocate grooming, a behavior that
doubtless accrues fitness benefits in terms of cub survival for the mother (fig-
ure 10.3b).
Dominance
Terms such as
dominance
are used to describe predictable aspects of repeated
dyadic interactions (i.e., relationships). The term
dominance
is a valuable con-
cept made controversial largely by a proliferation of definitions; Drews (1993),
having reviewed 13 definitions, concluded that dominance is characterized by
a consistent outcome in favor of the same individual within a dyad, within
which the opponent invariably yields rather than escalating the interaction.
This excludes many uses of dominance and, in particular, does not allow the
winner of a single agonistic interaction to be defined as dominant. A domi-
nance hierarchy may be produced by ordering the dominance relationships
between dyads. There may be a problem in determining what constitutes
yielding as an outcome. If a limiting commodity is involved, then yielding may
be allowing the “winner” deferential access to the commodity. Where no com-
modity is involved, a working definition may be used. For example, Chase
(1982) considered an overall yielding response to occur if a hen chicken deliv-
ered any combination of three strong aggressive contact acts when there was
more than a 30-minute interval after the third action during which the receiver
of the actions did not attack the initiator. A certain degree of subjective intu-
