An
interpretation of the "displacement
phenomenon"
Dalbir Bindra
McGill University, Montreal,
Canada
Animals that are prevented from continuing
some activity (e.g., attacking, copulating) tend
to engage either in the same sort of activity
toward another object or in a completely
different activity (e.g., grooming, preening). A
popular interpretation of this phenomenon among
psychologists and ecologists is in terms of a
displacement mechanism through which it is
assumed the energy of one reaction system is
drained off into another, following Freud's
early formulation. Bindra, rejecting this line
of explanation as vague and ad hoc, offers an
alternative explanation in terms of the
operation of three factors:
1. An obstructing event brings about an
increased level of excitation in the
animal.
2. This heightening of excitation alters the
relative probabilities of occurrence of the
various activities that exist in the animal's
repertoire, the condition of heightened
excitement favoring those activities which were
initially acquired or recently practiced at such
a high arousal-level and those activities that
have, in general, been practiced
frequently.
3. Any activity in the animal's repertoire
can occur only within a certain range of
variation of the sensory cues with which that
activity is associated. In support of his
thesis, Bindra offers the observation that many
so-called displacement activities, thumb-sucking
in children, grazing in sheep, and preening in
birds, have high habit strength.
He suggests that the man who is provoked by
his boss but does not act aggressively in the
office would be less likely to act aggressively
with his wife or children (rather than more
aggressively, as the displacement mechanism
theory would have it). Since he proposes that
the behavior following obstruction would be
determined by the sensory cues currently active
in the animal or human, not by any residual
'energy' made superfluous by the obstruction, he
predicts that the man provoked by his boss at
the office would react aggressively toward his
wife only if that is one of the activities for
which she is a cue. If she is a cue, rather, for
relaxing, he may instead 'cry on her shoulder'.
Bindra's thesis has the virtue that it suggests
easily achievable lines of experimental
work.
The observations that animals obstructed in the
execution of a particular ongoing or customary
activity (e.g. attacking, copulating tend either
to direct the same activity toward another
object or to engage in a completely different
activity (e.g. doodling, grooming, preening)
have traditionally been described as
'displacement phenomena'. Both psychologists and
ethologiste currently interpret these phenomena
in terms of some kind of displacement
phenomenon, which is assumed to displace the
'energy' or 'drive' from one reaction system to
another. This type of interpretation is vague
and ad hoc, and at best provides only a
redundant description of the observed phenomena.
The alternative interpretation proposed here
looks upon the problem of the occurrence of the
so-called displacement activities as a special
case of the general question of the factors
determining the occurrence of any activity that.
exists in an animal's repertoire. In particular,
it is suggested that all instances of
displacement phenomena can be adequately
accounted for in terms of the operation of three
factors: (a) an increase in the level of arousal
of the animal brought about by the obstructing
event, (b) the relative habit strengths of the
various activities in the repertoire of the
animal, and (c) the nature of the sensory cues
provided by the altered stimulus situation. This
formulation incorporates the important
ethological and psychological findings, and
provides an interpretation of displacement
phenomena which is not ad hoc and which suggests
new lines of experimental work.
I. The phenomenon and its current
interpretation
When an animal is prevented from engaging in
a particular activity, either by an
environmental obstacle or by interference from
some other ('conflicting') responses, that
activity may be said to be obstructed. Such
obstruction ('frustration') of an on-going,
customary, or in some sense 'expected' activity
affects the course of the animal's subsequent
behaviour. A sequence of events of this kind,
response A-obstruction-response B, has been
widely described as displacenuni phenomnan, and
the subsequent activity (response B) is labelled
displacernent activity.
Generally speaking, the term 'displacement.'
is used to describe two different types of
consequences of the obstruction of an activity
(or 'drive'). The first type includes cases in
which, when an opportunity arises, the animal
engages in the same general class of activity as
the one that was obstructed, but the activity is
directed towards a different object. Thus, a man
who, after some provocation, is prevented from
hitting his boss because of some interfering
'respect re8pouses', later, may (at least
according to folklore) act aggressively toward
his wife or children. Secondly, the term
'displacement', is employed to describe
phenomena in which, following the obstruction,
the animal shows some other, 'irrelevant', but
fairly specific, activity. Thus, a child
prevented from eating candy may start to suck
his thumb, or a sheep prevented from escaping a
noxious stimulation may begin to graze. In cases
of this type, the animal does not engage in the
activity that was originally obstructed, but in
some completely different activity. Ethologists
(e.g. Lorenz, 1935, 1941; Tinbergen, 1951, 1952)
employ the term 'displacement' in this sense
when, for example, they state that, if
conflicting responses obstruct fighting in a
skylark, or copulation in a duck, the animal
begins to preen or peck intermittently. The
various behavioural phenomena described by such
labels as 'substitution', 'sublimation', and
'displaced aggression' are all special cases of
the two types of consequence of obstruction
described above.
The currently popular interpretation of
these phenomena, in both psychological and
sthological writings, is in terms of a
displacement mechanism (Freud. 1913). Thus, it
is thought that, when an animal is prevented
from engaging in an activity (or 'expressing a
drive'), the particular response tendency or its
accompanying 'energy' remains active until it
can be dissipated either by 'displacing' it on
to an irrelevant object or into an irrelevant
activity. As Tinbergen has put it 'Our
hypothesis therefore is that the displacement
activities are outlets through which the
thwarted drives can express themselves in
motion' (1952, p. 12). Such a notion of a
displacement mechanism is quite inadequate to
explain displacement phenomena. It is vague and
ad hoc. When an animal is prevented from
engaging in an activity for which it is ready,
it obviously must show some activityif it is
still alive. Only two possibilities exist.
Either its new activity will resemble, to a
lesser or greater extent, the prevented
activity, or the new activity will be completely
different. In neither case is anything gained by
stating, post hoc, that it represents a
'displacement' of the original response
tendency, energy, or drive. Invoking this
hypothetical mechanism so arbitrarily provides
only redundant descriptions and is unproductive
of experimental analysis. In order to formulate
a meaningful and experimentally fruitful
hypothesis, the exact empirical variables that
control the occurrence of displacement
activities must be stated explicitly. (Actually,
to describe the phenomena under discussion as
displacement phenomena in to beg the question;
however, in order to avoid coining a new term, I
shall continue employing the term 'displacement
phenomena' osa descriptive label, without
accepting the 'displacement mechanism' as an
adequate explanation.)
A number of writers have already confronted
the difficult task of specifying the empirical
variables that determine the occurrence of
displacement activities. For example, Tinbergen
(1952) has discussed the roles of factors such
as initial posture and external stimulation, and
Andrew (l9SGa, b) of stimuli originating from
the body surface. Miller (1948) has
experimentally analysed some of the factors
operating in 'displaced aggression'. In the
following pages an attempt is made to
incorporate, the findings of ethological and
psychological workers into a. general framework
which would present an advance over the
displacement notion. The proposed framework
appears to have two advantages. First, it
suggests new lines of experimental work,
Secondly, it in not ad hoc; rather, it is a
special application of the same general bssic
concepts as are employed in accounting for other
types of behaviour.
II. An alternative interpretation
The general point of view adopted here is
the one I have more fully developed elsewhere
(Bindra, 1959). Basically, it assumes that the
problem of the analysis of any particular type
of behaviour can be reduced to two (empirical)
questions. First, how did the particular
activity develop in the organism's repertoire?
Secondly, what factors determine that this
activity, rather than any other activity of
which the organism is capable, will occur at a
given time and place, and the details (e.g.
latency. duration, errors) of the way u which
the activity occurs? In the present analysis of
displacement activity, the first, question can
he ignored; we can assume that the activities
usually described as displacement activities
(preening in birds, grazing in sheep, grooming
in chimpanzees. thumbsucking in the human
infant, and so on) have already developed in the
organism's repertoire. (The exact roles of
innate and experiential facti*s in the
development of these activities still remain to
be determined: see Bindra, 1959, chapters 3 and
4.) Thus, the question under discussion is one
of the factors that determine whether or to what
extent r will any given activity occur at a
particular time and place. To general. as I have
arcuied in the reference cited, four main sets
of factors completely determine the occurence of
any activity: habit strength of the activity,
senenry cues provided by the stimulus situation,
level of arousal of the organism, and state of
blood chemistry of the organism. In this
discussion an attempt is made to account for the
occurrence of the So-called displacement
activities in terms of the operation of the
first three of these factors. The discussion
involves a number of general propositions and a
consideration of their application displacement
phenomena.
`
(1) The level of arousal of an organism is
raised whenever it is exposed to an
environemental change or novel sensory
stimulation. (The term 'level of arousal'is
employed here to denote roughly the degree to
which an organism is excited rather than calm.
The low extreme end of this dimension is
represented by the state of deep sleep or
general anaesthesia, the high extreme end by the
state of panic or epileptic seizure. The
commonly employed indices of arousal include
such measures of physiological function as
electrical resistance of skin, muscle action
potentials, and the pattern of firing of nerve
cells within the brain. For a fuller discussion
of this concept, see Puffy (1951. 1957),
Liodsley (1951). ,Srhloeherg (1954.1957 Hebb
(1955), Malmo (1957) and Biodra (1959).) The
extent to which arousal level is raised depends
upon the exact nature of lie stimulus change:
for example, noxious stimulation (such as
electric chock or its threat) and socially
insulting events tend, in general, to raise
arousal level more than does lie presentation of
lights, noises and simple tasks. Now, the
starting-point in the description of the typical
displacement phenomenon is some type of
obstruction that is described as frustrating,
conflict-provoking, anxiety-producing,
stressful, or a situation of great "tension"
(Tinbergen, 1952). Whatever the exact nature of
these situations, they all involve,a change in
sensory stimulation of the type that
substantially raises the level pf arousal
('excess of drive'-Tinbergen), though the degree
of increase in arousal varies from situation to
situation and individual to individual. Thus,
the so-called displacement activities typically
occur when the animal is in a state of
heightened arousal. The heightened arousal level
typically lasts for some time after the
cessation of the event (i.e. change in sensory
stimulation) that initially produced it.
According to the present view. it is the
continued presence of the heightened arousal
level that is partly responsible for what the
animal does subsequently. To the present
context, this means that the partioular
(displacement) activities that occur in a given
situation depend upon the degree and duration of
the heightened arousal level.
(2) A shift in the level of arousal of an
animal alters the relative probabilities of
occurrence of the various activities that exist
in its repertoire. At very high (and very low)
levels of arousal there is an increase in the
relative probabilities of occurrence of two
types of activities: (a) activities that were
initially acquired or recently practiced at a
high arousal level, and (b) activities that have
a high habit strength, that is, those that have
been frequently practised. It is the high
habit-strength activities that are particularly
relevant here. According to the present view,
the activities that are usually referred to as
displacement activities are those that are
highly prepotent in the repertoire of organisms.
As Tinbergen has stated, an animal is apt to use
as outlets those patterns which for some reason
offer least resistance (1962, p. 1). An
enumeration of the various displacement
activities indicates that they are typically
high habit-strength activities. For example,
thumb-suking in children, grazing in sheep,
preening in birds are activities that are likely
to be over-practised in the repertoire of the
members of the particular species.
The above proposition states that activities
not prepotent in the repertoire of an animal are
not likely to occur when it is frustrated, made
anxious, put in a conflict situation, or aroused
in any other way. Thus, a man in whom aggressive
acts are not prepotent is less likely to act
aggressively in any situation than one in whom
aggressive acts have reached a high level of
habit strength. This statement implies that the
man who, on being reprimanded and, thus,
provoked by his boss, does not act aggressively
in the office situation is not likely to art
aggressively even when he sees his wife or
children. But the man who does act aggressively
in the office situation is also likely to act
aggressively in the home situation, provided his
arousal level remains high. These predictions
are directly opposed to those that might be made
on the basis of the traditional interpretation
in terms of a displacement mechanism. That would
predict that an individual who is provoked but
does not act aggressively ('suppresses his
anger') in the office situation is more likely
to act aggressively ('let go') in the absence of
his boss. These opposing predictions are subject
to an empirical test. In this connexion it is
interesting to note that, in Miller's (1948)
experiment, rats acted aggressively toward a
doll after they had obtained considerable
practice in attacking each other in the
experimental situation. The present
interpretation would predict that aggression
toward the doll would occur only in the case of
those rats in whom aggressive acts had acquired
a certain (undertermined) degree of prepotence.
Similarly, according to our formulation, birds
that normally preen more than others will also
be more likely to show preening when they are
aroused than birds in whom preening has not
reached the same level of habit strength. These
predictions can be tested experimentally. The
present suggestion of interaction between the
factors of habit strength and arousal makes it
unnecessary to postulate different
(undetermined) 'thresholds' (Tinbergen, 1962)
for the occurrence of various (displacement)
activities existing in the animal's
repertoire.
(3) Any activity in the repertoire of
animals can occur only within a certain range of
variation of the sensory ones with which that
activity is associated; when such sensory cues
are altered beyond a certain degree that
activity cannot occur at all. It is well known
that if the situation in which an animal
normally eats or copulates is altered beyond a
certain degree, the animal will cease, at least
for some time, to engage in the customary
activity; similarly, an animal which acts
aggressively toward a weaker animal may act
submissively toward a dominant one. In the
present context, this proposition means that,
when an animal has been aroused in some way, its
subsequent behaviour will depend upon the nature
of the sensory cues generated by the situation
in which it finds itself. If, for example, after
some frustration, a rat is placed in the
situation in which it normally copulates, then
the rat is likely to copulate; if it is placed
in an 'attack situation', it will tend to show
aggressive behaviour; and if it is placed in an
'eating situation', it will probably eat. In
short, the sensory ones associated with a
particular activity will evoke that activity,
except in so far as the customary activity may
be affected by the raised level of arousal. Thus
according to the present view, the behaviour
following any obstruction is determined by the
sensory cues currently active in the animal, and
not by any residual 'energy' made superfluous by
the obstruction. Th influence of initial posture
and environmental stimuli discussed by Tinbergen
(1952) is considered here as a special case of
the control on behaviour exerted by the current
(proprioceptive and exteroceptive) sensory cues.
Where.. only some of the relevant sensory cues
are present, an activity may occur only
incompletely: thus, while normally a bird may
peck and pick up food, if no food is in sight it
may peck and pick up nothing or may interrupt a
peck in progress.
The above proposition implies that
activities associated with more frequently
occurring sensory cues will be more likely to
occur following obstruction than activities
associated with less frequently occurring cues.
Whereas most activities of animals are dependent
upon appropriate environmental cues, there are
some that seem to be connected primarily to cues
arising from the animal's own body (Andrew,
l96h). Activities of this latter type include
grooming in rats, preening in birds,
thumh.siicking in infants, and tics and
stereotyped postural movements in most animals.
If the present proposition is accepted as true,
it is not surprising to note that it is
activities of this type that are most frequently
described as displacement activities. The
proposition also suggests a way to account for
the observation that, for example, a man
provoked by lus boss may not attack his boss but
may, a minute later, bang his own desk or
reprimand his own secretary. In such a case it
is likely (and this can be determined
independently of any particular incident) that
the boss-in-his-office situation does not
provide for this man the cues for aggressive
acts, but his own secretary and desk do.
Similarly, according to the present view, on
reaching home the man will act aggressively
toward his wife only if that is one of the
activities for which the wife is a cue; if his
wife is a cue for relaxing, he may 'cry on her
shoulder' (and this probably happens more
frequently than the current folklore leads one
to suspect).
III. Conclusion
The interpretation of displacement phenomena
proposed here looks upon all such phenomena as
resulting from the operation of three general
sets of variables: level of arousal, habit
strength and sensory cues. This formulation is
not considered as, in some sense, a final
explanation of displacement phenomena. Rather,
it is offered as a line of speculation that
points to the type of research that is likely to
lead to an adequate explanation. This approach
is an advance over the traditional
interpretation in two ways. First, it is not ad
hoc; rather it is a special application of the
same. basic concepts that are generally employed
in accounting for all types of behaviour.
Secondly, it appears to be more fruitful in
suggesting new lines of experimental work; in
particular, the exact effects of the three sets
of variables on the occurrence of various types
of (displacement) activities emerge as important
experimental problems.
