the concept and definition of dominance - drews 1993

Behaviour 125 (3-4) 1993, © E. J. Brill, Leiden

THE CONCEPT AND DEFINITION OF DOMINANCE IN ANIMAL BEHAVIOUR

by

CARLOS DREWS1)

(Department of Zoology, Cambridge University, Downing Street, Cambridge CB2 3EJ, U.K.)

(With 1 Figure) (Ace. 7-VII-1993)

Abstract

The concept of dominance has contributed greatly to our understanding of social structurc in animals. Over the past three decades, however, a variety of concepts and definitions of dominance have been introduced, leading to an ongoing debate about thc usefulness and mcaning of the concept. Criticisms aimed at one definition of dominance do not necessarilly apply to other definitions. Existing definitions can be structural or functional, refer to roles or to agonistic behaviour, regard dominance as a property of individuals or as an attribute of dyadic encounters, concentrate on aggression or on the lack of it, and be based either on theoretical constructs or on observable behaviour. Thirteen definitions of dominance are reviewed, and their usefulness assessed with respect to their descriptive value. The predictive and explanatory values of definitions are specific to the questions asked in each particular study and are not considered as criteria to judge the usefulness of the dominance concept. By virtue of its high descriptive value, the original definition of dominance by SCHJELDERUPp-EBBE (1922, Z.Psychol. 88: 226-252) emergcd as the basis to formulate a structural definition with wide applicability and which reflects the essencc of the concept: Dominance is an attribute of the pattern of rcpcated, agonistic interactions between two individuals, characterized by a consistent outcome in favour of the same dyad member and a default yielding response of its opponent rather than escalation. The status of the consistent winner is dominant and that of the loser subordinate. Dominance status refers to dyads while dominance rank, high or low, refers to the position in a hierarchy and, thus, depends on group composition. Dominance is a relative measure and not an absolute property of individuals. The discussion includes reference to the heritability of dominancc, application of dominance to groups rather than individuals, and the role of individual recognition and memory during agonistic encounters.

Introduction

Dominance is a keyword in most studies of social behaviour in gregarious

animals and has contributed greatly to our understanding of social struc

ture, Tables listing dominance studies in a diversity of animal taxa are

1) I thank S.K. ELTRI~<GHAM, G.W. NORTON, and P.C. LEE for valuable discussion.

284 CARLOS DREWS

provided by DEWSBURY (1982) and GAUTHREAUX (1978). Despite the fact that dominance is such an important and widely used concept, there is

still no agreement regarding its meaning. SCH]ELDERUPP-EBBE (1922)

introduced the concept of the peck-order, later to be called dominance,

into the behavioural sciences. He vividly described his observations on

the peck-order of domestic fowl, the dynamics of the hierarchy, and the

determinants of rank. \VILSON (1975) summarized different types of domi

nance hierarchies found in animals. HArm (1986) provided an ample

discussion of the different categories found among dominance relation

ships and rigorously defined the terms commonly used in studies of

dominance. Other conceptual discussions about dominance can be found

in VAN KREVELD (1970), FEDIGAN (1982) and DUNBAR (1988).

A lively debate has underlined the application of dominance in behav

ioural studies over the past three decades (e.g. BERNSTEIN, 1981). GARTLAN

(1968) criticized the different interpretations of dominance because these

often led to ambiguity. He further criticized the fact that the term

dominance is often used without a definition or else is arbitrarily

redefined to fit the findings. ROWELL (1974) pointed out that the defini

tion of dominance is elusive. Investigators are far from a consensus on

how to define and measure dominance (BERNSTEIN, 1981), leading to

disparate opinions regarding its function and evolution. BERNSTEIN (1981)

concentrated on primates but his review of the problems associated with

the concept of dominance has general application. His article is accom

panied by comments from various investigators and thus provides an

overview of the dominance debate and lack of concensus at that time.

One of the central problems of the dominance debate has been that

critics have not always explicitly specified which definitions they advocate

and which they criticize. This has kept the debate going since the criti

cisms may have been justified with respect to a particular definition but

not to others. In this paper, an overview of the diversi ty of definitions of

dominance found in the animal behaviour literature is presented and the

usefulness of each definition assessed with respect to furthering our

understanding of social structure and behaviour. Elimination of some

definitions and finding the common denominator of others lead to a

synthesis illustrating the essence of dominance in behavioural studies.

This synthesis is condensed in the definition of dominance proposed in

the concluding section.

285 THE CONCEPT AND DEFINITION OF DOMINANCE

Categories of d.ornfnance definitions

The terms winner, loser, submissive, subordination and aggression are

part of the specialized vocabulary surrounding the dominance concept.

These terms are defined and used here as follows:

Winner: the contestant that expresses consummatory behaviour according to its initial goal (BAENNINGER, 1981; HAND, 1986). Winner/loser refers to the outcome of one single contest.

Submissive: submissiveness is an active response to an aggressive action by another individual (HANBY, 1976) in which yielding or surrendering are displays given by the loser (HAND,

1986). Submissive behaviour refers to single contests.

Subordination: to lose consistently certain conflict encounters (HAND, 1986). Subordination refers to a pattern based on several contests.

Aggression: actual attacks, threats of attack or encroachments; signals which suggest that attack may occur can be called aggressive (HAND, 1986).

Dominance definitions can be separated into those based on empirical

observations and definitions based on theoretical constructs (GAGE, 1981,

HINDE & DATTA, 1981). These have been referred to as "data-language"

and "theory-language" definitions respectively by HINDE & DATTA

(1981). GAGE (1981) distinguishes two approaches to the study of domi

nance: in the first, the investigator formulates in theory-language the

conditions which must be met by a useful application of the term domi

nance, then derives a testable hypothesis and lets the results of empirical

inquiry support the definition of dominance or else lead to its rejection. In the second approach, the investigator assumes the existence of domi

nance, asserts an operational definition, and proceeds to demonstrate the

utility of the term and definition. This latter approach is similar to the

data-language definitions mentioned by HINDE & DATTA (1981), in which

a particular behavioural interaction is given the name "dominance inter

action". More broadly, dominance is used to describe a particular kind or

set of observable interactions. The dominance definitions based on

empirical observations can in turn be subdivided into structural and

functional ones (BERNSTEIN, 1981). Structural dominance definitions

describe the pattern of an observable type or set of interactions without

referring to their function, whereas functional definitions describe domi

nance from the point of view of its apparent function.

The distinction between definitions based on empirical observations

and theoretical postulates, as well as between structural and functional

definitions is used in this discussion to broadly characterize the definitions

286 CARLOS DREWS

of dominance prescnted below. A further distinction between definitions

is whether they describe agonistic or non-agonistic dominance relation

ships (BERNSTEIN, 1981). First, the definitions of dominance based on

empirical observations are presented. These are ordered from broad

definitions to more specific ones and, as such, they are not mutually

exclusive. Then, a definition based on theoretical constructs is given.

Some definitions are included which are not explicitly referred to in the

literature, but which help in the process of categorization.

Coxrrrrron definitions of d omdnanoe

Definitions based on empirical observations.

1. "Privileged role": animals in a role which subjectively represents a

privileged position with respect to others are dominant. This definition is

illustrated by WILSON'S (1975) description of the dominance hierarchy of

food transfer from forager bees (subordinates) to nurses (dominant).

There is no overt aggression in the relationship and the subordinate bees

acquire dominant status as they grow older. This is a non-agonistic

dominance definition.

The remaining definitions include agonistic behaviour as part of the

dominance concept. First, definitions (2.-4.) are listed which consider

dominance to be an attribute of the individual. In subsequent definitions

(5.-13.) dominance is considered a relative measure, an attribute of

dyadic encounters or relationships and not a property of individuals.

2. "Reproductive status": reproductive dominance in social insects refers

to differences in reproductive status such that the reproductive individual

is the dominant and the non-reproductive ones are subordinates (WILSON,

1975). This structural definition could be regarded as a case of the

"privileged role" definition. The usc of overt aggression by the reproduc

tivcs, howcvcr,justifies a separate mcnt ion of this definition. Wh~ll two or

more paper wasp (Polistes sp.) females start a nest together, one becomes

the egg layer while the others become workers. The queen establishes her

dominant position and controls the other wasps by direct aggression

(\VEST, 1967; EBERHARD, 1969). Here, dominance refers to the reproduc

tive condition achieved and not to the pattern of aggressive interactions.

THE CONCEPT AND DEFINITION OF DOMINANCE 287

If, however, the investigator bases dominance status on the pattern of

aggression, then reproductive dominance is a functional definition

derived from the "dominance is aggressiveness" definition (see below).

3. "Dominance is aggressiveness": a dominance hierarchy is the set of

sustained aggressive-submissive relations among a group of animals

which coexist within one territory (WILSON, 1975). WILSON (1975) is

concerned with " ... dominance behaviour mediated by aggression and

inferentially based upon natural selection at the level of the individual. .. ".

The occurrence of aggressive contests over resources among any social

group of animals is indicative of dominance relationships. The expression

of the dominance system IS based on individual variation III

aggreSSIveness.

4. "Dominance IS a trait that conveys rank": a dominant individual

routinely wins encounters with significantly greater than chance proba

bility against a variety of conspecific opponents. This occurs because that

individual has more of a trait called dominance (or aggreSSIveness or

assertiveness) than do the losers (BAENNINGER, 1981).

5. "Winner is dominant, loser is subordinate": dominance status IS a

synonym for winner and loser used to describe the outcome of any single

dyadic encounter, regardless of whether or not the contest is escalated.

6. "Successful combatant": dominance ranks are established on the basis

of dyadic contests resembling a competition. Generally each dyad meets

on one or few occasions in which the decisive contest takes place. CLUT

TON-BROCK et at. (1979) established the dominance rankings of male red

deer on the basis of fighting success in the rutting season. Similarly, the

ranks of elephant seals are determined through the outcome of escalated

fights in the breeding season (LEBOEUF, 1974). The observed pattern of

interactions resembles HAND'S (1986) aggressive dominance definition, in

which the winner uses or seems willing to use the most aggression.

Dominance scores based on overall fighting success belong to this defini

tion (e.g. BOYD & SILK, 1983, ENS et al., 1990). Another example are

lekking species, in which the contest is sometimes decided on the basis of

acoustic or visual displays and may include escalated fights. This defini

288 CARLOS DREWS

tion neither implies that escalation is avoided nor that individuals recog

nize each other and incorporate past agonistic experiences into contest

decisions.

7. "Dominance IS lack of aggressiveness": dominance refers to the

"peaceful" nature of encounters between animals, in which escalated

fights do not take place and conflicts are resolved using non-agonistic

assessment or submissive behaviour. VESSEY (1981) advocates a use of the

term dominance that conveys its likely function, namely control of

resources and minimum energy expenditure through the use of displays to

control the behaviour of the receiver. Learning from past encounters and

individual recognition are not necessary conditions under this definition.

Typically, an individual recognizes a feature in the opponent which

indicates superiority (e.g. size, weaponry, quality of display) and submits

without a fight. High predictability of outcomes seems necessary under

this definition of dominance. Dominance status is assigned after a single

contest.

8. "Consistent winner of agonistic contests": when A consistently wins

agonistic encounters against B then A is dominant and B subordinate.

This definition is characterized by the asymmetry in the outcome of a

series of contests of any type and implies that A and B meet repeatedly. It

neither implies that high levels of aggression are avoided nor that individ

ual recognition and memory of other contests play a role in contest

decisions.

9. "Consistent winner in a given context": dominance is a descriptive

term for individuals that consistently win dyadic encounters in a given

context (HAND, 1986). A dominance relationship is described for each

competitive context. Dyadic relationships can be pure or mixed, since

they may exhibit different kinds of relationship for different conflict

contexts (HAND, 1986). This definition emphasizes the role of context in

determining the outcome of interactions (e.g. LEE, 1983).

10. "Priority of access to resources": dominance is by definition priority

of access to resources (VAN KREVELD, 1970; MORSE, 1974; SYME, 1974;

WILSON, 1975; GAUTHREAUX, 1978; WOLFE, 1984; WAGNER &


GAUTHREAUX, 1990). Por-r- & DEVORE (1979) define dominant/ subordi

nate as the winner/loser in contests over resources. The winner is the

contestant which displaces the other or appropriates the opponent's

resource (e.g. CLUTTON-BROCK et al., 1979). Avoidance of escalation dur

ing contests is not a requisite for dominance. It refers to obtaining what

one wants by winning a fight or without having to fight for it (RALLS,

1976). The functional, central statement of dominance is that particular

individuals in social groups have regular priority of access to resources in

competitive situations (CLUTTON-BROCK & HARVEY, 1976). Dominance

describes an asymmetry in the outcome of such contests. High ranking

individuals can be identified by observing the outcome of contests over

resources or by identifying the holders of resources directly (e.g. the male

with the largest harem is by definition the alpha male).

II. "Peck-order" after SCHJELDERUPp-EBBE (1922): if A pecks at Band B

never or seldom reciprocates then A is dominant to Band B is subordi

nate to A (SCHJELDERUPp-EBBE, 1922; ALLEE, 1938). A is the despot and B

is typically afraid of it, adds SCHJELDERUPp-EBBE (1922). According to the

original descriptions of the way in which dominance relationships

develop (SCHJELDERUPp-EBBE, 1922; ALLEE, 1938), dominance implies

that individuals recognize each other. Dyadic dominance status is

assessed on the basis of one agonistic interaction type, namely pecking,

and refers to its consistent, unidirectional pattern over time.

12. "Modified peck-order definition": a slight modification of the "peck

order" definition is to include more than one agonistic interaction type in

the assessment of dominance status. BARRETTE & VANDAL (1986)

rephrased the "peck-order" definition of dominance summarizing its

essence: dominance is an attribute of a relationship between two individ

uals, whenever an asymmetry in the outcome of agonistic interactions is

measured. If a dominant seldom has to fight to supplant a subordinate,

the subordinate is repelled without a need to escalate, then a true domi

nance relationship exists. HAND'S (1986) social dominance relationships

between individuals who meet repeatedly corresponds to this definition.

In agonistic dominance relationships the directionality of the agonistic

encounters is not dependent upon location, as opposed to territoriality

(KAUFMANN, 1983). In order to explain this dominance pattern it has been

290 CARLOS DREWS

argued that one member of the dyad in question consistently submits at

the onset of any encounter as a function of the past history of interactions

with the other member (BERNSTEIN, 1981). Consequently, it may be

assumed that the subjects discriminate between different opponents. A consistent change in the response pattern of two individuals in agonistic

conflicts, following their first contest, indicates that a relationship

between the subjects has been established. The defeated member of the

dyad submits or emits a terminating response in subsequent encounters

with the other member without escalation. On the basis of such a change

from symmetric to asymmetric initial responses in subsequent agonistic

interactions, dyads with a dominance relationship can be differentiated

from those without, since in the latter case each encounter is contested

before yielding. The investigator should not assume that a dominance

relationship exists in each dyad, because unresolved or egalitarian rela

tionships may exist (BOYD & SILK, 1983; HAND, 1986). In summary, the

"modified peck-order definition" is characterized by i) asymmetry in the

outcome of diverse agonistic interactions, ii) avoidance of escalated

encounters mediated by the subordinate's deferring behaviour, and iii)

influence of past encounters on subsequent responses to opponents. The

latter point implies that discrimination on the basis of individual identity

is a necessary element of dominance relationships.

Dominance definition based on theoretical constructs.

The theoretical approach to the study of dominance was introduced by

HINDE (1978) and GAGE (1981) who postulate that dominance must

represent a collection of observable actions, the validity of which can be

empirically verified. The inter-correlation between the observables deter

mines the definition and usefulness of the term or else justifies its

rejection.

13. "Intervening variable": dominance is postulated in theory as an

intervening variable between independent variables and a set of depen

dent variables which are intercorrelated and covary equally in the major

ity of dyads (HINDE, 1978; HINDE & DATTA, 1981). Experience, for exam

ple, influences the direction of agonistic interactions via the intervening

variable "dominance". A dominance/ subordinance relationship implies

THE CONCEPT AND DEFINITION OF DOMINANCE 291

one in which aggression is reduced or (overtly) absent. The pattern of

asymmetry in the various interactions, including non-agonistic ones, may

vary according to the situation. HINDE (1978) uses the term "agressive

dominance" as a subcategory of dominance, to which other, non-agonis

tic, interactions may be related. If aggression and non-agonistic behav

iour are correlated, then both can be considered to be under the influence

of dominance. The "intervening variable" definition is also used by

BAENNINGER (1981), CANDLAND & HOER (1981), and GAGE (1981), among

others.

General attributes of dOininance definitions

There is general agreement about some potentially confounding terms

which should not be equated to dominance. Dominance does not imply

leadership (ALLEE, 1938), and, thus, it is not to be confounded with

"control" (HINDE, 1978): e.g. in baboon (Papio cynocephalusi consortships,

the female may be controlling many aspects of the male's behaviour such

as the direction of movement, while the male remams dominant to the

female.

The association between dominance and aggression differs widely

between the different definitions of dominance (Table 1). Dominance is

generally associated with conflict resolution during agonistic encounters.

The "privileged role" definition of dominance is an exception, in which

status assignement is independent of any agonistic encounters. Fig. 1

shows the minimum set of options encountered on the way to a definition

of dominance which refers to agonistic behaviour. Each possible pathway

in the flowchart leads to a different definition.

'When agonistic encounters are the basis to determine the directionality

of the relationship, definitions of dominance differ with regard to the

expression of overt aggression shown during conflict resolution. In some

definitions overt aggression is the diagnostic feature of a dominance

system. Other definitions do not discriminate between non-aggressive

and escalated dominance interactions and pool all agonistic encounters to

determine status. Yet other definitions explicitly limit the applicability of

the dominance concept to those instances in which conflict resolution

does not include overt aggression or escalated fights (Table 1). In "peck

order" definitions, overt aggression by the dominant individual may be

292 CARLOS DREWS

TABLE 1. Attributes of common definitions of dominance

Ernpdr-ica! observation definitions

Non-agonistic behaviour: Dominance as a role description: - "privileged role"

Agonistic behaviour as part of definition: - "reproductive status" Dominance as a property of the individual: - "dominance is aggressiveness" - "dominance is a trait that conveys rank" Dominance as an attribute of dyadic encounters: - "winner is dominant, loser is subordinate" - "successful combatant" - "priority of access to resources" - "dominance is lack of aggressiveness"

Consistent outcome of dyadic interactions: - "consistent winner of agonistic contests" - "consistent winner at a given context"

Escalation usually avoided: - original "peck-order" - "peck-order" modified

this study -> - essence of dominance

Theoretical construct definition: - "intervening variable"

Attributes

S, P, LD, NT

S/F, (AG), LD, NT

S, AG, LD, IH

S, AG, LD, IH NT S, AG, LD S, AG, LD F, (AG), (ASY), HD S, AG, P, HD S, AG, ASY, HD

S, AG, ASY, HD S, AG, ASY, IR, P, HD S, AG, ASY, IR, P, HD S, AG, ASY, P, HD

AG, NI, HD/LD

S = structural definition, F = functional definition, AG = pattern of agonistic interactions reflects dominance, ASY = asymmetric outcome of contests within a dyad, TR = individual recognition involved, IH = dominance inheritable, NI =dominance not inheritable, P = "peaceful" (no overt aggression during conflict resolution), brackets ( ) = not a necessary condition. LD = low descriptive value, HD = high descriptive value.

the start of an interaction but contests are generally not escalated, given

the default yielding response of the subordinate. These definitions are

included among those in which conflict resolution is usually a "peaceful"

event.

While some definitions consider dominance to be an attribute of the

individual ("dominance is aggressiveness" or "a trait that conveys rank"

definitions), others view dominance as an attribute of dyadic relationships

or of single interactions. Under definitions which do not regard domi

nance as a relationship between individuals, dominance status within

dyads is assigned on the basis of the outcome of a single contest or the

subjects are ranked according to the ratio of individuals defeated to

individuals lost to. Conversely, under those four definitions which regard

dominance as an attribute of a relationship between two individuals,


IBASIS: AGONISTIC BEHAVIOUR

~ ~

DEFINITION AS THEORETICAL CONSTRUCT

F1JNCTIONAL STRUCTURAL

I V

ESCALATED CONTESTS INCLUDED OR EXCLUDED FROM DEFINITION

v v

OUTCOME OF ONE CONTEST CONSISTENT OUTCOME FROM SEVERAL IS SUFFICIENT CONTESTS BETWEEN SAME INDIVIDUALS

CONTEXTS

RELATIONSHIP

v

EACH CONTEXT TREATED SEPARATELY

OBSERVED PATTERN OF INTERACTIONS CALLED DOMINANCE

DOMINANCE DEFINITION

Fig. I. Flowchart illustrating points of decision when dominance definitions related to agonistic behaviour are formulated.

294 CARLOS DREWS

dominance status is assigned on the basis of the outcome of several

conflicts, if a consistent asymmetry in favour of one dyad member is

observed (Table I). The dyadic asymmetry in contest outcome is a

possible, but not necessary element of the "priority of access to resources"

definition.

The asymmetry in the direction of the outcome of contests arises from

one individual consistently winning and the other consistently losing

consecutive encounters. Ideally, status assignment should only be made in

those dyads in which the asymmetry is statistically significant over a set

period of time. A dominance relationship is just one possible relationship

between two individuals. There are unresolved and egalitarian relation

ships in which there is no clear asymmetry in the outcome of contests

(HAND, 1986). A dominance relationship between individuals, thus

implies that the same individuals meet and resolve conflicts on several

occasions (HINDE & STEVENSON-HINDE, 1976) in a clearly unidirectional

pattern.

The word "relationship" is ambiguous in the context of dominance

definitions. A dominance relationship can be understood as a mental

experience of the individuals concerned. This view has been criticized by

ALTMANN (1981) and is associated with those definitions of dominance

which imply that individual recognition operates during interactions (e.g. "peck-order" definitions). A simpler use of the term "relationship" refers

strictly to data, to the interaction between the role of winner and loser

among two individuals during a series of agonistic encounters. The latter

use corresponds to the "consistent winner of agonistic encounters" and

"the consistent winner at a given context" definitions.

Some advocates of dominance as an attribute of dyadic relationships

have argued that dominance presupposes individual recognition (e.g. WYNNE-EDWARDS, 1962; ROWELL, 1974; HINDE & STEVENSON-HINDE,

1976). Past conflicts may influence the outcome of future encounters (e.g. mice Mus sp.: GINSBURG & ALLEE, 1942; rhesus monkeys Maraca mulatta:

ROSE et al., 1972, 1975). Individual recognition, however, is not a neces

sary condition to explain those cases in which one individual consistently

submits to another, familiar individual without an escalated fight taking

place. At the onset of each conflict the opponents may assess one another

on the basis of a morphological feature or display which correlates well

with competitive ability (KODRIC-BROWN & BROWN, 1984) regardless of

----------


past experiences with the same opponent. This pattern of "peaceful"

conflict resolution corresponds to the "dominance is lack of aggressive

ness" definition. Individual recognition and memory of past encounters is

an important ability when such predictive cues are not available and

fighting ability can only be assessed in escalated contests or inferred from

observation of the opponent's behaviour towards other, known members

of the social group.

In conclusion, individual recognition is not a necessary condition to

produce the behavioural pattern observed under any of the dominance

definitions, although advocates of the "peck-order" definition envision

dominance as an identity relationship between two individuals. The

hypothesis that individuals use individual recognition in their assessment

of contest success has to be tested in each particular case.

Domdrrarrce and heritability

Dominance can only be inheritable when it is a property of individuals

(Table 1). Several breeding studies claim to have selected particularly

dominant individuals or to show that dominance status has an inheritable

component (e.g. Nlo0RE, 1990; DEWSBURY, 1990; and references therein).

An investigator can successfully breed for dominant individuals on the

basis of the "dominance is aggressiveness" definition. Aggressiveness has

been shown to have an inheritable component in several species (e.g. chickens, Gallus domesticus: GUHL et al., 1960; dogs, Canisfamiliaris: SCOTT

& FULLER, 1965; sticklebacks, Gasterosteus aculeatus: BAKKER, 1986; sil

vereyes, Zosterops lateralis: KIKKAWA et al., 1986; fruit flies, Drosophila

melanogaster: HOFFMANN, 1988). On the other hand, breeding experiments

suggest that there is a genetic component to the determinants of rank,

when dominance is defined as an attribute of relationships (DEWSBURY,

1990).

Explicit definition of dominance and careful formulation ofthe conclu

sions of breeding experiments are essential to avoid misunderstandings

about the heritability of dominance. Claims regarding the heritability of

dominance traits are bound to evoke criticism by the advocates of domi

nance as an attribute of conflict resolution and of dominance as a descrip

tion of role. Dominance as an attribute of an interaction or of a relation

ship between two individuals is a relative measure which cannot be

296 CARLOS DREWS

selected for (GARTLAN, 1968; ROWELL, 1974; BERNSTEIN, 1981; BARRETTE,

1987). Natural selection operates on absolute, competitive properties of

individuals and not on relative dominance status. Dominance ranks

depend on the group composition and are, therefore, not an inheritable

property of an individual either (DUNBAR, 1988). Dominants and subordi

nates behave differently, but these are not genetically distinct roles, or

genetically fixed alternative strategies, since subordinates are fully capa

ble of behaving as dominants given the appropriate circumstances for a

change in status (MCGUIRE et al., 1984). Furthermore, most individuals in

a hierarchy are simultaneously subordinate to some and dominant to

other members of the group. The issue of the heritability of dominance

illustrates how a given definition of dominance may have applications

which are incompatible with other definitions of the term.

Descriptive, predictive and explanatory value of dominance

One limitation of definitions based on observations rather than theory is

that these are not open to empirical investigation. If another definition is

proposed, there is no methodology to determine which of the definitions

is appropriate and the question remains one of semantics rather than

science (GAGE, 1981). Nevertheless, criteria such as the descriptive, pre

dictive and explanatory value can be used to differentiate between

definitions.

The descriptive value of dominance.

Dominance has a high descriptive value when its definition refers to

something for which no other single term existed before and the term is

useful when it can be used to differentiate that something from something

else. In addition, dominance can be used as a descriptive tool to test the

possibility of merging, and hence simplifying, categories of behaviour

(CANDLAND & HOER, 1981). Thus, the descriptive value of a dominance

definition is high if it serves efficiently the process of categorization. The

descriptive value is an absolute property of a definition, irrespective of the

theoretical context in which it is used. Contrary to some contentions

(BERNSTEIN, 1981; HINDE & DATTA, 1981), the descriptive value of a

dominance definition may justify keeping the definition without it being

predictive or explanatory. Neither the predictive nor the explanatory


value are inherent absolute qualities of the definition but rather a func

tion of the theoretical context in which the concept is used and of the

questions asked. In assessing the usefulness of the dominance concept,

one can first estimate its descriptive value, then test empirically whether

the definition is supported by the data, and lastly assess the explanatory

value of using the concept for a particular question.

In the following definitions, dominance has a low descriptive value

because it is used as a synonym of other, already existing terms, such as

aggressiveness, winner, or an arbitrarily chosen status or role: "domi

nance is aggressiveness", "winner is dominant, loser is subordinate",

"successful combatant", "reproductive status", and "the privileged role"

definition. The use of dominance following these definitions does not help

to describe, predict or explain any phenomena better than do its syn

onyms. SYME (1974) argued, with respect to context specific asymmetries

in the outcome of agonistic interactions, that if each group has a large

number of "dominance orders" then the concept is effectively useless. An

asymmetry in the outcome of particular interactions is not a sufficient

justification to introduce a dominance concept, either as a descriptive

tool or an explanatory mechanism (DREWS, 1973; SYME, 1974).

The "dominance is a trait that conveys rank" definition is used to

collectively refer to all those behavioural characteristics of an individual

which are decisive in the outcome of an agonistic conflict. Dominance in

this sense has a high descriptive value. Dominance definitions which

include consistency in the direction of the outcome of dyadic contests

and/or lack of aggressive escalation during conflict resolution, also have a

high descriptive value in that they describe formerly unrecognized

phenomena.

In general, the functional definition of dominance, i.e. "priority of

access to resources", describes the access to resources mediated by ago

nistic contests. Por-e & DEVORE (1979) refer more specifically to the

pattern of context specific access to resources. This definition equates

dominance with non-egalitarian access to resources, and consequently

has a high descriptive value since there was no other term to dennote that

phenomenon.

Dominance in theory language is a hypothetical construct to investi

gate the common denominator of certain categories of behaviour (CAND

LAND & HOER, 1981), and is similar to constructs such as "stress",

298 CARLOS DREWS

"motivation" and "drives" (MAXIM, 1981). Dominance is a useful con

cept because it may enable simplifying our description: by using domi

nance as an intervening variable between independent and dependent

variables, we would reduce the number of links needed to describe the

interaction between both sets of variables (HINDE, 1978). Economy in

description is a first step in explanation (HINDE, 1978). When agonistic

rank has a high predictive value in determining the outcome of other

dyadic relationships, it is useful to abstract dominance as a description of

some aspects of social structure (DEAG, 1977; HINDE, 1978). The descrip

tive value of dominance as an intervening variable is a function of the

inter-correlation between different interaction types and can be tested

empirically. In female primates, for instance, well inter-correlated vari

ables could be "supplants", "grooming", and "submissive", possibly with

a weaker link to "priority of access" (HINDE & DATTA, 1981). We know,

however, that there is lack of consistency even within agonistic categories

since context is likely to influence the pattern observed (Por-r & DEVORE,

1979; LEE, 1983; HAt'lD, 1986). If the dependent variables are unlikely to

be well correlated then, following GAGE (1981), the intervening variable

definition can be rejected. The usefulness of dominance, however, does

not depend on a correlation between dominance order and other aspects

of social behaviour. Dominance is still useful in the description of a

particular type of social structure, in which by some criterion of bossing

related to aggression, the individuals can be arranged in a hierarchical

order (HINDE, 1978).

The predictive value of dominance.

Dominance has a high predictive value when the direction or outcome of

a given interaction can be accurately predicted on the basis of past

observations of dominance behaviour. Dominance is, however, a variable

which remains dynamic and, thus, predictability needs neither to be

perfect nor permanent; ontogeny alone guarantees that physical abilities

vary (BERNSTEIN, 1981). "Prediction" (sensu BERNSTEIN, 1981) alludes to

the degree of confidence with which the statistical asymmetry in dyadic

contests predicts the outcome of any given subsequent conflict within the

same dyad. Cardinal dominance ranks have been calculated on the basis

of the probability of winning contests (BOYD & SILK, 1983). Hence,


dominance is useful as a shorthand term to indicate that the outcome of

an agonistic interaction between two individuals is predictable with some

practical level of certainty (ROWELL, 1974). "Prediction" can also be used

to refer to the reliability with which the statistical asymmetry in dyadic

contests predicts the direction of other, non-agonistic interactions outside

the context of dominance.

The predictive value of a dominance definition is only of interest,

therefore, when the investigator uses dominance relationships to antici

pate the behaviour of individuals. The level of accuracy of the prediction

is not an attribute of the definition itself but of the behaviour of the study

animals, and the usefulness of such a prediction depends on the questions

asked in each particular case. Accurate prediction alone can be a heuris

tic value of a dominance definition without it being explanatory. This

approach has yielded contrasting results, for some authors claim that

dominance does predict a wide variety of social interactions (e.g. RICH

ARDS, 1974; SEYFARTH, 1976, 1980; CHENEY, 1978) and others point out

the lack of correlation between different measures of dominance (GAR

TLAN, 1968; SYME, 1974; BERNSTEIN, 1981; BRAIN, 1981). Variation in the

definitions of dominance contributes to the discrepancy in such results.

The explanatory value of dominance.

It has been contended that the concept of dominance as an explanation of

behaviour requires that it should actually predict priority of access to

resources at least sometimes (RICHARDS, 1974; DEAG, 1978). This require

ment, though, implies a priori that dominance influences the pattern of

access to resources or else that priority of access to resources be part of

the definition of dominance. Predictions about patterns of resource

access, however, are not necessary for the concept of dominance still to be

explanatory. Dominance has a high explanatory value when the introduc

tion of the term and measurements of dominance reduce the magnitude

of formerly unexplained variance in the data. The explanatory value

arises from finding which variables depend on dominance since, in this

way, dominance improves our understanding of social organization

(BERNSTEIN, 1981). It is difficult, nevertheless, to define which is an

independent measure of dominance and which are its dependent vari

ables (BERNSTEIN, 1981). The explanatory value can be an inherent qual

300 CARLOS DREWS

ity of theoretical definitions of dominance (see next paragraph) but is not

a necessary property of structural definitions. It is rather a function ofthe

theoretical context in which the concept is used and of the questions

asked by the investigator.

With regard to theoretical definitions of dominance, HINDE (1978)

argued that the concept of dominance as an intervening variable has

explanatory value if the following conditions are satisfied: (I) the investi

gation is concerned with more than one dyad, (2) each dyad has a

multiplex relationship involving comparable complementary interactions

in which one bosses the other, and (3) the pattern of inbalance in those

interactions is similar in the different dyads. The usefulness of dominance

increases with the variety of correlations among dependent variables

(HINDE & DATTA, 1981). In contrast, CANDLAND & HOER (1981) argued

that dominance as an intervening variable is a descriptive tool which

serves the process of categorization and is not explanatory. Dominance as

an intervening variable does not make any inferences about the direction

of causality in the observed correlations among dependent variables.

Moreover, dominance as an intervening variable is, by definition, not an

empirical variable. Consequently, it cannot be incorporated into an

empirical model to attempt to improve the fit between predictions and

observations. Thus, dominance as an intervening variable can be a pow

erful descriptive tool but is of low explanatory value with respect to

questions about the nature of the observed behaviour.

The (in)adequacy of dOIninance definitions

Much of the controversy around the concept of dominance has arisen

from the variety of definitions and usages given to the term. Most of the

definitions of dominance are structural and as such, they are all justified

on semantic grounds (GAGE, 1981). Parsimony, however, dictates that

there should be an upper practical limit to the number of new definitions

created for the same term and that their justification should depend on

their descriptive power. Ideally, for the concept to be more useful and to

reduce ambiguity, all users of dominance should refer to one and the

same phenomenon. In the following discussion I evaluate the adequacy of

the dominance definitions listed above and synthesize the essence of a

unitary dominance concept for behavioural studies. The criteria used to


categorize the definitions into appropriate and less appropriate are their

respective descriptive values and their affinities to the original definition

of dominance as described by SCH1ELDERUPp-EBBE (1922). The original

definition is not only taken as a reference because it happens to be the

first definition, but also because it has a high descriptive value and called

our attention to a distinct behavioural phenomenon. It is noteworthy that

in view of the controversy around dominance definitions, SADE (1981)

suggested to look back at the early literature on dominance, which is clear

and straightforward in the definitions and use of the concept (e.g. ALLEE,

1938; COLLIAS, 1944).

Most definitions of dominance listed above, including the original

"peck-order" definition, have in common that they refer to agonistic

behaviour. Dominance should be reserved to its already widely estab

lished use for patterns of interaction, in which the direction of comple

mentarity is initially established through aggression, andfor in which

aggressive behaviour is potentially present (HINDE, 1978). Its usefulness

should not be diluted with other cases of complementarity in interactions,

e.g. as referred to by WILSON (1975) with respect to food passage in honey

bees. For this reason, as well as because of their low descriptive value, the

"privileged role" and the "reproductive status" definitions of dominance

are inadequate. Also, those definitions which refer to dominance as a

synonym of aggressiveness, winnerfloser or "successful combatant" are

inadequate on the basis oftheir low descriptive value. Dominance should

not be defined as a synonym of any other already existing term.

BAENNINGER (1981) understands dominance as a trait which combines

several different intercorrelated variables (see HINDE, 1978), and explic

itly defines dominance as a property of individuals. Similarly, WILSON'S

(1975) mention of dominance as equivalent to aggressiveness implies that

dominance is a variable, individual trait. Definitions of dominance as a

trait of individuals ("dominance is aggressiveness", "dominance is a trait

which conveys rank") are incompatible with those definitions which

regard dominance as an attribute of dyadic encounters or relationships,

including SCH1ELDERUPp-EBBE'S "peck-order" definition.

Discontent with the "dominance is aggressiveness" definition has been

emphasized by several authors. It is generally agreed that dominance

refers to the patterning of interactions between individuals and not to the

amount of aggressive behaviour that they show (e.g. JAY, 1965;

302 CARLOS DREWS

KAUFMANN, 1967; CHALMERS & ROWELL, 1971; ROWELL, 1974; SYME,

1974; BERNSTEIN, 1976; 1981; HINDE, 1978). Rather, aggression can be

viewed as an expression of dominance (BERNSTEIN, 1976). Whilst domi

nance may depend on aggression or potential aggressiveness, it does not

necessarily correlate with them (LOCKWOOD, 1979; BERNSTEIN, 1981). In a

principal factor analysis of wolf (Canis lupus) behaviour, the absolute level

of agonistic behaviour was not part of the dominance factor detected

(LOCKWOOD, 1979). The results of a dominance and communication

analysis in children support the theoretical conception of dominance, that

emphasizes the relationship between individuals rather than the coercive

behaviour of some group members (CAMRAS, 1984).

Although aggressiveness is known to vary between individuals (e.g. CUHL et al 1960), the levels of aggression observed in natural agonistic

contests do not necessarilly reflect these differences. The game theoretical

approach to the study of aggressive competition (e.g. PARKER, 1974;

CARYL, 1980; MAYNARD-SMITH, 1982; ENQUIST & LEIMAR, 1990) suggests

that all individuals have the potential to express aggression, but that the

aggression observed is a circumstantial product of the cost/benefit ratio

of using it. Hence, the directionality of aggression commonly used to

assign dominance status is not necessarilly related to an aggressive prop

erty of the individuals concerned, but rather to the fact that some individ

uals defer upon being attacked because their chances of winning a given

contest are low. A definition of dominance based on the outcome of

several dyadic conflicts relates more to SCHJELDERUPp-EBBE'S (1922)

"peck-order" definition than the "dominance IS aggressiveness"

definition.

In the previous paragraphs, those definitions of dominance were con

sidered inadequate which were not related to agonistic interactions at all,

had a low descriptive value because they referred to dominance as a

synonym of an already existing term, and/or described dominance as an

inherent attribute of individuals rather than of interactions between

them. Those definitions which refer to dominance as an attribute of

conflict resolution patterns (Table I) are now discussed, bearing in mind

that SCHJELDERUPp-EBBE'S definition is characterized by the asymmetry in

the outcome of dyadic encounters and the fact that conflicts are generally

resolved by the deference of the loser without escalation. The only defini

tions which regard asymmetry and lack of escalation as necessary ele


ments of dominance are the original "peck-order" definition and the

"modified peck-order definition". Definitions which consider one of these

conditions as necessary include the "dominance is lack of aggressiveness"

(lack of escalation), "consistent winner of agonistic contests" (asym

metry), and the "consistent winner at given contexts" definition (asym

metry). Asymmetry and lack of escalation mayor may not be given in the

conflicts considered in the "priority of access to resources" definition,

which, thus, departs more noticeably from the "peck-order" definition.

The "priority of access to resources" definition of dominance has been

subject to criticism (e.g. SVME, 1974; BERNSTEIN, 1981; BARRETTE & VAN

DAL, 1986). Attention on advantages to dominants leads to frame a

definition of dominance based on priority of access to incentives, while

ignoring structure in favour of consequences (BERNSTEIN, 1981). Such

functional definitions are problematic when different strategies yield

similar benefits (examples in BERNSTEIN, 1981). If dominance is measured

on access to only some, specific incentives it is then of no explanatory

value to understand the principles of social organization.

The use of the "priority of access to resources" definition is oflimited

value to the study of dominance, because dominance more generally

refers to all conflict resolution instances, while not all conflicts are over

resources (HAND, 1986). Further, studies using the "priority of access to

resources" definition of dominance sometimes claim to describe an effect

of dominance on resource access, a circular statement which arises from

measuring dominance on the basis of the pattern of resource access (e.g. GAUTHREAUX, 1978; SVME, 1974; ApPLEBV, 1980). This functional defini

tion is, hence, inadequate to study whether high dominance rank per se is

advantageous. The interpretation of an aggressive order must be

restricted to aggressive behaviour unless it can be correlated with a

quantitative demonstration of general priority of access to resources

(SVME, 1974). In addition, when measuring dominance on the basis of

access to incentives, there is sometimes the problem of identifiying what

are incentives (BERNSTEIN, 1981). The constraints of the "priority of

access to resources" definition illustrated above, nevertheless, do not

make it less valid with respect to the "peck-order" definition. The "prior

ity of access to resources" definition, however, is concerned with a

particular kind of interaction, namely contests over resources, irrespec

tive of a dyadic consistency in their outcome and of the degree of

304 CARLOS DREWS

escalation involved. For this reason, this definition is incompatible with

respect the dominance concept of SCH]ELDERUPp-EBBE (1922). A similar

argument applies to the "intervening variable" definition, which also

lacks affinity with the original definition of dominance.

Few authors have objected to the "peck-order" definition. HINDE &

DATTA (1981) argued that if dominance/ subordinance is assessed in terms

of only one dependent variable (here: pecking), then dominance is merely

descriptive and has no explanatory value. Dominance would be merely a

way of describing the data in other words. I argued above that the

explanatory value is not a property of the definition but of the context in

which it is used. Clearly, the original definition was concerned with only

one kind of interaction, namely pecking, which would limit its appli

cability to other taxa. The "modified peck-order definition" includes

other complementary agonistic interactions in an analogous way to

SCH]ELDERUPp-EBBE'S treatment of pecking. This modified definition also

derives its high descriptive value from referring to dominance as a consis

tent pattern in dyadic interactions whereby deference rather than esca

lated fights are the rule, a phenomenon which deserves a description on

its own. Memory and individual recognition are implicit in the "peck

order" definition as proximate mechanisms to explain the deference

behaviour. These mechanisms may apply in some cases but need not be

necessary for the consistent deference behaviour to be observable. Mech

anisms and function should not form part of the definition and used

instead within hypotheses concerning the causation of dominance

relationships.

The feature recognition criterion and dODlinance relationships

Broad definitions of dominance do not preclude the study of dominance

across different sizes, sexes and age categories, and even between groups,

populations or species (e.g. GAUTHREAUX, 1978). SEYFARTH (1981) argued,

however, that it makes little functional sense to lump together all age-sex

classes in studying dominance, because we know about the variety of

different selective presures acting on each class. If the outcome of contests

can be predicted by location (territoriality) or a relational attribute which

correlates with the direction of outcomes (e.g. size, age, sex) then it is not

useful to describe each of them as a special type of agonistic dominance


(BERNSTEIN, 1981). Such a view tacitly implies that dominance relation

ships exist as long as the investigator does not identify one single reliable

predictor of contest outcome. From this perspective, dominance relation

ships reflect the investigator's ignorance about the identity and interrela

tion of determinants of conflict outcomes and dominance would cease to

exist when these are understood. This example emphasizes the impor

tance of explicitly specifying exactly how dominance is defined (or per

ceived) by each investigator. However, if dominance is viewed as the

consistent asymmetry in the outcome of contests between two individuals

whereby the subordinate generally defers to the dominant without escala

tion, then identifying the determinants of this pattern is a necessary step

towards explaining it and no identified determinant should invalidate the

phenomenon.

In a rigorous application of the "peck-order" definition of dominance,

memory of past encounters and individual recognition determine the

behaviour in dominance dyads. Such a definition implies a relationship

between each of two individuals and thus, it refers to dominance as a

much more specific phenomenon than just asymmetrical outcomes in

non-escalated contests within a dyad. When observed agonistic patterns

are equivalent to those expected by a peck-order dominance, we need to

know whether identity of the opponent is used to predict the outcome of a

contest, before a peck-order dominance relationship is inferred. This

question can be approached by witnessing the first contests between

unfamiliar individuals and then observing the corresponding change in

agonistic response over time. In stable social groups, changes in status

suggest that identity recognition may be used by opponents instead of

predictive morphological features when such features do not change as

frequently as dominance status.

ALTMANN (1981) regards dominance relationships as cognitive experi

ences which should be reserved to the higher primates and humans. He

argues that as long as it is not shown that individuals react to a relation

ship, rather than to agonistic behaviour past or present or correlations

thereof, parsimony dictates that relationships need not be inferred. If a

general feature of the opponent (like sex or age) is used at the onset of

each encounter to decide whether the contest should be escalated or

avoided then past experience of the opponent and its identity would be

irrelevant. The feature-recognition criterion is probably used during most

306 CARLOS DREWS

dominant/ submissive interactions between individuals which meet only

once, as explained in the "dominance is lack of aggression" definition.

BERNSTEIN (1981) regards the dominant individual as taking an active

part in the dyadic dominance relationship when it acknowledges immedi

ate submission rather than attacking. There is no need to postulate an

identity relationship on that ground, if the dominant individual follows

the simple rule of not attacking when the opponent submits immediately

(a behavioural feature). Por-r- & DEVORE (1979) discuss the adaptive value

of stopping further attack once the opponent has submitted, in contexts in

which a relationship between the two individuals is irrelevant.

Individuals, sex, groups, or species: the units of domfrrarrce

The concept of dominance has been mostly utilized to characterize the

behaviour of individuals. It has been also applied to the relationship

between categories such as sexes, groups, and species. The working

hypothesis in studies of intersexual dominance (e.g. RALLS, 1976;

DESROCHERS et al., 1988) is that one sex may exclude the other from

limiting resources. Such an exclusion is referred to as dominance, resem

bling the "priority of access to resources" functional definition. Domi

nance is not to be interpreted as the agent causing resource monopoliza

tion because dominance is measured on the basis of the outcome of all

agonistic encounters, most of which may be over resources. Dominance

in this context is descriptive, not explanatory.

Intergroup dominance is similar to the dominance relationships in

dyads of familiar individuals, because in intergroup contests often the

entire group behaves as a unit which is known to the opponent group

from previous encounters. Intergroup dominance in wild rhesus monkeys

has been described on the basis of supplants, avoidance, or fights between

groups (SOUTHWICK et al., 1965). This usage of the term corresponds, at

the group level, to the "consistent winner of agonistic contests"

definition.

Interspecific dominance after MORSE (1974) is the priority of access to

resources that results from successful attacks, fights, chases or supplanting

actions present or past. It represents one mechanism of interference

competition. For example, gulls (Larus sp.) dominate curlews (Numenius

arquata), while curlews dominate small waders (ENS et al., 1990). ~WAGNER


& GAUTHREAUX (1990) refer to MORSE'S (1974) definition as the definition

of dominance in general. GAUTHREAUX (1978) discussed the ecological

significance of interspecific dominance following the "priority of access to

resources" definition. Other claims that the concept of dominance can be

applied to groups, populations and species (VVILSON, 1975) have referred

to the "winner is dominant, loser is subordinate", or the "dominance is

lack of aggression" definitions. Such definitions were shown above to be

inadequate at the level of individuals, and the same reasoning applies to

their application to units of higher order.

A further problem of applying the concept of dominance to interactions

outside the familiar social group is that this use is not compatible with

definitions of the term that imply a relationship between the interactants.

Advocates of the latter definition argue that dominance hierarchies are

only possible in small groups because individual aquaintance is a prereq

uisite (WYNNE-EDWARDS, 1962; ROWELL, 1974). In the usage of domi

nance beyond the confines of the familiar group, the individual identity of

the opponent and past agonistic experiences with that particular individ

ual are often irrelevant to the decisions of the contestants. In interspecific

dominance interactions the dyadic conflict is probably settled by recogni

tion of species specific attributes of the opponent.

The crucial criterion to justify the use of dominance for higher order

categories is not the choice of category, but rather the definition of

dominance used. When dominance is used beyond the level of dyadic

interactions between single conspecifics there is the danger that analogies

of dominance will be confused with homology (BERNSTEIN, 1981).

The essence of d orrri'narrce i synthesis and definition

Despite a great variety of dominance definitions, it is generally agreed

that dominance refers to agonistic behaviour. Several definitions of domi

nance were rejected on the grounds of their low descriptive value. The

original definition of dominance by SCHJELDERUPp-EBBE (1922) described

a distinct phenomenon in chicken, which is regarded here as the basis for

a more general concept of dominance with broader applicability. The

high descriptive value of this dominance concept justifies its use; predic

tion and explanation are applications of dominance, which originate in

the particular field of interest of each investigator. The essence of domi

308 CARLOS DREWS

nance which emerges from the above discussion IS summarized in the

following, structural definition of the term:

Dominance is an attribute of the pattern of repeated, agonistic interac

tions between two individuals, characterized by a consistent outcome in

favour of the same dyad member and a default yielding response of its

opponent rather than escalation. The status of the consistent winner is

dominant and that of the loser subordinate.

Operational definitions of dominance, based on the above definition, can

be formulated in each particular study according to the choice of subjects

and the theoretical framework used. Although this definition concen

trates on dyadic interactions (because these are readily observable), it

does not preclude the possiblity that the outcome is influenced by the

nearby presence of other individuals, which may tacitly or overtly support

one of the contestants (see KAWAI (1958, 1965) for an introduction to the

concept of dependent rank).

A semantic clarification complements this definition: dominance status

and dominance ranks are different measures (HINDE, 1978; BERNSTEIN,

1984; BARRETTE & VANDAL, 1986; DUNBAR, 1988). This distinction

applies to the definitions of dominance which refer to the pattern of

dyadic encounters (Table 1). Dominance status refers to a relationship

between two animals and depends on an animal's attributes compared to

those of the other, while rank refers to the relative position within a group

and, hence, depends on group composition. Dominance status refers to

the status of one individual within a given dyad and can be either

dominant or subordinate according to the direction of the statistically

significant asymmetry in the outcome of several contests. Dominance

rank refers to the position of one individual in a dominance hierarchy and

can be expressed at an ordinal level either numerically, in greek letters (a = top rank, Q = bottom rank, SCHJELDERUPp-EBBE, 1922) or qualitatively

as high or low, but not as dominant or subordinate.

In general, dominance ranks are calculated after assessment of domi

nance status in all possible dyads of the group. The resulting hierarchy

can be linear, but does not necessarilly have to be so (ApPLEBY, 1983).

Dyadic dominance/ subordinance relationships and the dominance hier

archy are not necessarily related and the first does not imply the existence


of the other in a social group (HINDE, 1978). The limitations of ordinal

ranks, in which by definition the distance between adjacent ranks is the

same, have lead some investigators to develop indices which reflect the

more realistic "dominance distances" that separate animals in a hier

archy (e.g. BOYD & SILK, 1983; ARCESE & LUDWIG, 1986; ZUMPE &

MICHAEL, 1986; DREWS, in prep.).

With respect to the above definition, dominance has been viewed from

different perspectives. At a general level dominance is seen as a descrip

tive tool (e.g. CANDLAND & HOER, 1981). ALTMANN (1981) and SEYFARTH

(1981) maintain that dominance relationships and dominance hierarchies

have no function and are not ends in themselves or cognitive experiences

of the animals, but simply shorthand, structural descriptive terms used by

the observer. BERNSTEIN (1981) argued that dominance can be regarded

as a relative measure used to illustrate one attribute of a dyadic relation

ship. SMUTS (1981) sees dominance relationships as a useful estimate of an

individual's ability to influence the behaviour of another for its own

benefit, through that individual's power to inflict physical injury. Por-t- &

DEVORE (1977) view agonistic dominance as an unavoidable product of

cost/benefit considerations during competitive interactions. They, conse

quently, frame dominance under the theory of games for aggressive

competition.

Other investigators concentrate on the fact that escalated fights are

generally avoided and regard dominance as a dimension ofthe communi

cation system (e.g. CHANCE, 1956; MAXIM, 1981). The subordinate may

signal defeat before the dominant completes the attack or immediately

when intention to attack is signaled by stereotyped movements or vocaliz

ations. This is seen as evidence that a communication system has evolved

(SADE, 1981). The lack of agreement in the way that investigators perceive

dominance is evident, and preference for one interpretation or the other

is bound to remain arbitrary.

The structural definition proposed above simplifies the debate around

the dominance concept because it makes no assumptions about the men

tal experiences of the subjects or about those of us investigators who use

the concept. This definition provides a frame for future studies on domi

nance which can deal with more specific aspects, such as the role of

memory and individual recognition, as well as the identification of deter

minants and consequences of dominance status.

310 CARLOS DREWS

Literature cited

ALLEE, W.C. (1938). The social life of animals. - W.vV.Norton, New York. ALTMANN, S.A. (1981). Dominance relationships: the Chcshire cat's grin? - Behav. Brain

Sci. 4, p. 430-431. ApPLEBY, M.C. (1980). Social rank and food access in red dcer stags. - Behaviour 74, p.

294-309. -- (1983). The probability of linearity in hierarchies, - Anim.Behav. 31, p. 600-608. ARCESE, P. & LUDWIG, D. (1986). Improving estimates of dominance based on ratios. -

Condor 88, p.106-107. BAENNINGER, R. (1981). Dominance: on distinguishing the baby from the bathwater. -

Bchav. Brain Sci. 4, p. 431-432. BAKKER, T.C.M. (1986). Aggressiveness in sticklebacks (Gasterosteus aculeatus L.): a bchav

iour-genetic study. -- Behaviour 98, p. 1-144. BARRETTE, C. (1987). Dominance cannot be inhcrited. - TREE 2: 251 -- & VANDAL, D. (1986). Social rank, dominance, antler size, and access to food in snow

bound wild woodland caribou. - Behaviour 97, p. 118-146. BERNSTEIN, LS. (1976). Dominance, aggression and reproduction in primate societies.

J. theor.Biol. 60, p. 459-472 -- (1981). Dominance: The baby and the bathwater. - Behav. Brain Sci. 4. p. 419-457. -- (1984). The adaptive value of maladaptive behavior, or you've got to be stupid in

order to be smart. - Ethol.Sociobiol. 5, p. 297-303. BOYD R. & SILK, J.B. (1983). A method for assigning cardinal dominance ranks.

Anim.Behav. 31, p. 45-58. BRAIN, P.F. (1981). The concept of dominance also has problems in studies on rodents.

Behav. Brain Sci. 4, p. 434-435. CA~lRAS, L.A. (1984). Children's verbal and nonverbal communication in a conflict situa

tion. - Ethol.Sociobiol. 5, p. 257-268. CANDLAND, K.D. & HOER, J.B. (1981). The logical status of dominance. - Behav. Brain

Sci. 4, p. 436-437. CARYL, P.G. (1980). Escalated fighting and the war of nerves: gamcs theory and animal

combat. - In: Perspectives in ethology 4-. (P.P.G. BATESON & P.H. KLOPFER, eds). Plenum Press, New York, p. 199-224.

CHALMERS, N.R. & ROWELL, T.E. (1971). Behavior and female reproductive cycles in a captive group of mangabeys. -- Folia primatol. 14, p. 1-14.

CHANCE, M.R.A. (1956). Social structure of a colony of Macaca mulatta. BritJ.Anim.Behav. 4, p. 1-13.

CHENEY, D.L. (1978). Interactions of immature male and female baboons with adult females. - Anim.Behav. 26, p. 389-408.

CLUTTON-BROCK, T.H. & HARVEY, P.H. (1976). Evolutionary rules and primate societies. - In: Growing points in ethology (P.P.G. Bateson & R.A. HINDE, eds). The University Press, Cambridge, p.195-237.

--, ALBON, S.D., GIBSON, R.M. & GUINESS, F.E. (1979). The logical stag: adaptive aspects of fighting in red deer (Cervus elaphus L.). - Anim.Behav. 27, p. 211-225.

COLLIAS, N.E. (1944). Aggressive behavior among vertebrate animals. - Physiol. Zool. 17, p.83-123.

DEAG,J.M. (1977). Aggression and submission in monkey societies. - Anim.Behav. 25, p. 465-474.

-- (1978). The adaptive significance of baboon and macaque social behaviour. - In: Population control by social behaviour. (P. EBLINGAAND & D.M. STODDART, eds). Institute of Biology. London, p. 83-ll3.

DESROCHERS, A., HANNON, SJ. & NORDIN, K.E. (1988). Winter survival and tcrritory acquisition in a northern population of black-capped chickadees. - The Auk 105, p. 727-736.


DEWSBURY, D.A. (1982). Dominance rank, copulatory behavior, and differential reproduction. - QRev.Biol. 57, p. 135-159.

-- (1990). Fathers and sons: genetic factors and social dominance in deer mice, Peromiscus maniculatus. - Anim.Behav. 39, p. 284-289.

DREWS, D.R. (1973). Group formation in captive Galago crassicaudatus: notes on the dominance concept.- Z. Tierpsychol. 32, p. 425-435.

DUNBAR, R.UvL (1988). Primate social systems. - Croom Helm, London & Sydney. EBERHARD, MJ.W. (1969) The social biology of polis tine wasps. - Miscellaneous Publica

tions, Museum of Zoology, University of Michigan, Ann Arbor 140, p. 1-10 I. ENQUIST, M. & LEIMAR, O. (1990). The evolution of fatal fighting. - Anim.Behav. 39, p.

1-9. ENS, B., ESSELINK, P. & ZWARTS, L. (1990). Kleptoparasitism as a problem of prey choice: a

study on mudflat-feeding curlews, Numenius arquata. -- Anim.Behav. 39, p. 219-230. FEDIGAN, L. (1982). Primate paradigms: Sex roles and social bonds. - Eden Press,

Montreal. GAGE, F.H. (1981). Dominance: measure first and then define. - Behav. Brain Sci. 4, p.

440-441. GARTLAN, j.S. (1968). Structure and function in primate society. - Folia primatol. 8, p.

89-120. GAUTHREAUX, S.A.jr. (1978). The ecological significance of behavioural dominance. - In:

Perspectives in ethology 3. (P.P.G. BATESON & P.H. KLOPFER, eds). Plenum Press, New York, p. 17-54.

GINSBURG, V. & ALLEE, W.C. (1942). Some effects of conditioning on social dominance and subordination in inbred strains of mice. -- Physiol. Zool. 15, p. 485-506.

GUHL, A.M., CRAIG,j.V. & MUELLER, C.D. (1960). Selective breeding for aggressiveness in chickens. - Poultry Sci. 39, p. 970-980.

HANBY, j. (1976). Sociosexual development in primates. - In: Perspectives in ethology 2. (P.P.G. BATESON & P.H. KLOPFER, eds). Plenum Press, New York, p. 1-67.

HAND, J.L. (1986). Resolution of social conflicts: dominance, egalitarianism, spheres of dominance, and game theory. - QRev.Biol. 61, p. 201-220.

HINDE, R.A. (1978). Dominance and role - two concepts with dual meaning. j.soc.bioI.Struct. I, p. 27-38.

-- & DATTA, S. (1981). Dominance: an intervening variable. - Behav. Brain Sci. 4, p. 442.

-- & STEVENSON-HINDE,J. (1976). Towards understanding relationships: dynamic stability. - In: Growing points in ethology. (P.P.G. BATESON & R.A. HINDE, eds). Cambridge University Press, New York, p. 451-479.

HOFFMANN, A.A. (1988). Heritable variation for territorial success in two Drosophila melanogaster males. - Anim.Behav. 36, p. 1180-1189.

JAY, P. (1965). The common langur of North India. -- In: Primate behavior, field studies of monkeys and apes. (1. DEVORE, ed.). Holt, Rinehart and Winston, New York, p. 197-249.

KAWAI, M. (1958). On the system of social ranks in a natural group ofJapanese monkeys, (parts I & II). - Primates I, p. 111-148 (in Japanese).

-- (1965). On the system of social ranks in a natural group ofJapanese monkeys: Basic rank and dependent rank. - In: japanese monkeys: A collection of translations (K. IMANISHI & S.A. ALTMANN, eds). Emory University Press, Atlanta, p. 66-86.

KAUFMANN, J.H. (1967). Social relations of adult males in a free-ranging band of rhesus monkeys. - In: Social communication among primates. (S.A. ALTMANN, ed.). University of Chicago Press, Chicago and London: p. 73-98.

-- (1983). On the definitions and functions of dominance and territoriality. - Biol.Rev. 58, p. 1-20.

312 CARLOS DREWS

KIKKAWA, L., SMITH,J.N.M., PRYS-JONES, R., FISK, P. & CATTERALL, C. (1980). Determinants of social dominance and inheritance of agonistic behavior in an island population of silvereyes (;:;:,osterops lateralisi. - Behav.Eco!.Sociobio!. 19, p. 165-169.

KODRIC-BROWN, A. & BROWN,J.H. (1984). Truth in advertising: the kinds of traits favoured by sexual selection. - Am. Nat. 124, p. 309-323.

VAN KREVELD, D. (1970). A selective view of dominance- subordination relations in mammals. - Genetic Psycho!. Manogr. 81, p. 141-173.

LEBoEUF, B.]. (1974). Male-male competition and reproductive success in elephant seals. - Am. Zoo!' 14, p. 163-176.

LEE, P.C. (1983). Context specific unpredictability in dominance interactions. - In: Primate social relationships. (R.A. HINDE, cd.). Blackwell Scientific Publications, Oxford, p. 35-44.

LOCKWOOD, R. (1979). Dominance in wolves: useful construct or bad habit? - In: The behaviour and ecology of wolves. (E. KLINGHAMMER, ed.). Garland Press, New York, p. 225-244.

MAXIM, P.E. (1981). Dominance: a useful dimension of social communication. - Behav. Brain Sci. 4, p. 444-445.

MAYNARD-SMITH, J. (1982). Evolution and the theory of games. - Cambridge University Press, Cambridge.

MCGUIRE, M.T, RALEIGH, M.J. & BRAMMER, G.L. (1984). Adaptation, selection, and benefit-cost balances: implications of behavioral-physiological studies of social dominance in male vervet monkeys. - Etho!.Sociobio!. 5, p. 269-277.

MOORE, A.J. (1990). The inheritance of social dominance, mating behaviour and attractiveness to mates in male Nauphoeta cinerea. - Anim.Behav. 39, p. 388-397.

MORSE, D.H. (1974). Niche breadth as a function of social dominance. - Am. Nat. 108, p. 818-830.

PARKER, G.F. (1974). Assessment strategy and the evolution of fighting behaviour. j. theor.Bio!. 47, p. 223-243.

Por-r-, J.L. & DEVORE, 1. (1979). Aggressive competition and social dominance theory: synopsis. - In: The great apes. (D.A. HAMBURG & E.R. MCCOWN, eds). The Benjamin/Cummings Publishing Co., Menlo Park, p. 317 -338.

RALLS, R. (1976). Mammals in which females arc larger than males. - QRev.Bio!. 51, p. 245-276.

RICHARDS, S.M. (1974). The concept of dominance and methods of assessment. Anim.Behav. 22, p. 914-930.

ROSE, R.M., GORDON, TP. & BERNSTEIN, 1.S. (1972). Plasma testosterone levels in the male rhesus: influences of sexual and social stimuli. - Science, 178, p. 643-645.

--, BERNSTEIN, LS. & GORDON, T.P. (1975). Consequences of social conflict on plasma testosterone levels in rhesus monkeys. - Psychosom. Medicine, 37, p. 50-61.

ROWELL, TE. (1974). The concept of social dominance. - Behav. Bio!. II, p. 131-154. SADE, D.S. (1981). Patterning of aggression. - Behav.Brain Sci. 4,p. 446-447. SCHJELDERUPp-EBBE, T. (1922). Be itrage zur Sozialpsychologie des Haushuhns.

Zeitsch.f.Psycho!. 88, p. 226-252. SCOTT, J.P. & FULLER, J.L. (1965). Genetics and the social behavior of the dog.

University of Chicago Press, Chicago. SEYFARTH, R.M. (1976). Social relationships among adult female baboons.

Anim.Behav., 24, 917-938. -- (1980). The distribution of grooming and related behaviors among adult female

vervet monkeys. - Anim.Behav. 28, p. 798-813. -- (1981). Do monkeys rank each other? - Behav. Brain Sci. 4, p. 447-448. SMUTS, B. (1981). Dominance: an alternative view. ~- Behav. Brain Sci. 4, p. 448-449. SOUTHWICK, C.H., BEG, M.A. & SIDDIQI, M.R. (1965). Rhesus monkeys in North India.

In: Primate behavior. Field studies of monkeys and apes. (L DEVORE, cd.). Holt, Rinehart and Winston, New York, p. 111-159.


SYME, GJ. (1974). Competitive orders as measures of social dominance. -- Anim.Eehav. 22, p. 931-940.

VESSEY, S.H. (1981). Dominance as control. - Eehav.Erain Sci. 4: 449. WAGNER, SJ. & GAUTHREAUX, S.A. Jr. (1990). Correlates of dominance in intraspecific and

interspecific interactions of song sparrows and white-throated sparrows. Anim.Eehav. 39, p. 522-527.

WEST, MJ. (1967). Foundress associations in polistine wasps: dominance hierarchies and the evolution of social behavior. - Science 157, p. 1584-1585.

WILSON, E.O. (1975). Sociobiology. The new synthesis. - Harvard University Press, Cambridge.

WOLFE, L.A. (1984). Female rank and reproductive success among Arashiyama E Japanese macaques (Macacafuscata). - Int. J. Primatol. 5, p. 133-143.

WYNNE-EDWARDS, V.C. (1962). Animal dispersion in relation to social behaviour. - Oliver and Eoyd, London/Edinburgh.

ZUMPE, D. & MICHAEL, R.P. (1986). Dominance index: A simple measure of relative dominance status in primates. - Am. J. Primatol. 10, p. 291-300.

the concept and definition of dominance - drews 1993

Documents

dominance rank

social structure

social structurc inanimals

decades e

andthe determinants

aconsistent outcome

thedynamicsof thehierarchy

leadingto disparate