Laterality of Facial Expressions of Emotion: Universal and Culture-Specific Influences
Laterality of facial expressions of emotion: Universal and culture-specific influences
Manas K. Mandal 1
Nalini Ambady 0
0 Tufts University , Medford, MA , USA
1 Indian Institute of Technology - Kharagpur , India
Recent research indicates that (a) the perception and expression of facial emotion are lateralized to a great extent in the right hemisphere, and, (b) whereas facial expressions of emotion embody universal signals, culture-specific learning moderates the expression and interpretation of these emotions. In the present article, we review the literature on laterality and universality, and propose that, although some components of facial expressions of emotion are governed biologically, others are culturally influenced. We suggest that the left side of the face is more expressive of emotions, is more uninhibited, and displays culturespecific emotional norms. The right side of face, on the other hand, is less susceptible to cultural display norms and exhibits more universal emotional signals.
“we respond to gestures. . . in accordance with an
elaborate and secret code that is written nowhere,
known by none and understood by all” [120, p. 892].
Human beings rely extensively on nonverbal
channels of communication in their day-to-day emotional as
well as interpersonal exchanges. The verbal channel,
language, is a relatively poor medium for expressing
the quality, intensity and nuancing of emotion and
affect in different social situations. Nonverbal channels
of communication that transmit emotional messages
include facial expressions, paralanguage, gestures, gaze,
posture, and proximal behavior. Amongst these
channels, the face is thought to have primacy in signaling
affective information [
]. First, the face is exposed
to the full view of others in order to facilitate social
interaction. Second, the amount (especially in short
period of time) and type of information (e.g., emotional,
attitudinal) conveyed by the face are relatively easy to
]. It is not surprising, then, that the
face has been a central focus of research on the
communication of emotion, beginning with the classic work of
Darwin , and followed up by pioneers in the field
such as Tomkins [
], Izard [
], and Ekman .
During the past two decades, a great deal of
attention has been paid to the issues of the lateralization and
universality of facial expressions of emotion. The
focus of the lateralization issue has been on the relative
role of the two cerebral hemispheres in the
understanding, expression and subjective experience of emotion.
Primary questions of interest include: (a) Is there a
hemispatial advantage in the identification of facial
expressions of emotion?, (b) To what extent do the two
hemifaces differ in the expression of positive or
negative emotions?, and, (c) Which hemisphere is more
activated during the subjective experience of different
The focus of the universality issue has been on the
panculturality of recognition and expression of facial
emotion. Primary questions of interest that have been
examined in the literature include: (a) Are facial
emotions recognized similarly across all cultures?, (b) To
what extent does culture influence the expression of
emotion?, and, (c) Are there any culture-specific
The purpose of the present article is to review
evidence for the laterality and universality of facial
expressions of emotion and to ascertain their possible
relationship. To review the evidence, computerized databases
(involving search engines like PsychInfo,
ScienceDirect, PubMed, Google) were utilized, in addition to
examining relevant journals. The selection criteria for
studies involved including any that dealt with the
functional laterality of facial expressions of emotion, with
the major focus being on the recognition and
expression of emotion. Studies dealing with the neural
pathways in the recognition or the anatomical pathways in
the expressions of facial emotions were not included.
Experimental as well as clinical evidence was reviewed
in order to garner further evidence for the functional
laterality of facial expression of emotion. Studies
examining the universality and culture-specificity of
facial expression of emotion were also included. No
attempt was made to determine the efficacy of any
particular theoretical position that supported either a
universal or a culture-specific perspective. Instead,
evidence for both perspectives was examined by focusing
on laterality studies.
The impetus behind the examination of the
lateralization of emotion was drawn mainly from recent
observations that emotion regulation is not restricted to
subcortical and limbic structures. A substantial body
of research has confirmed the role of the neocortex in
the understanding, expression and subjective
experience of emotion [
]. Interestingly, this work has
largely overlooked evidence that facial expression, and
judgment of emotions differ widely amongst cultures
as a function of emotion type and hedonic valence (but
]), and the degree of subjective experience
of emotion [
2. Laterality & facial emotions
The study of laterality provides a window into the
understanding of behavioral and neural processes [
especially those pertaining to emotion [
]. The term
“laterality” indicates anatomic and functional
differences between the two halves of the brain [
Anatomical differences are referred to as biological
asymmetry (like the relative size, shape of the two
hemispheres, brain-ventricle ratio, skull size, etc.) and
functional differences are referred to as behavioral
asymmetry. Behavioral asymmetry is determined
either via central (e.g., split-visual-field, dichotic
listening, dichhaptic techniques, etc.) or peripheral (e.g.,
facedness, handedness, footedness, etc.) measures.
The central measures directly assess perceptual
processes in the two hemispheres. Peripheral measures
indirectly ascertain the role of two hemispheres in motor
Two approaches are generally taken in examining
hemispheric involvement in affective processing:
experimental approaches, in which normal functions of
the brain are studied usually with participants whose
brains are intact (although, at times brain-damaged
patients are also tested in experimental studies); and
clinical approaches, the goal of which is to examine the
degree and magnitude of functional impairment following
localized brain damage [
]. Both approaches deal
with the hemispheric involvement in affective
functioning, although observations derived from these two
approaches are not directly comparable.
3. Lateralization in the identification of facial emotion: Experimental and clinical evidence
Table 1 presents the experimental evidence for
perceptual asymmetry of facial expressions of emotion.
This evidence, in general, suggests that the left
visualfield (a contralateral function of the right hemisphere)
is superior in the identification of facial expressions of
emotion, especially negative emotions. Most of these
studies utilize a split visual-field technique in which
facial expressions are presented to two visual-fields (with
the observer’s eyes fixed on a central point) for 180 ms
or less. This method ensures that left and right visual
images initially reach the contralateral hemispheres.
The left visual-field superiority for facial emotion
identification has been found to be robust across studies
that used photographs, cartoons, or schematic
drawings. Left visual-field superiority has also been found
when stimulus photographs are presented under neutral
or free-viewing conditions.
These experimental findings have been substantiated
by clinical evidence. For example, studies on clinical
samples reveal that there is strong evidence that
righthemisphere damage relative to left-hemisphere damage
impairs the perception of emotional expressions
displayed via the face [
comprehension of emotional prosody , the judgment of
emotion-laden lexicons [
], the understanding of an
emotional tone of voice [
], and the appreciation of
humorous stimuli [
]. Moreover, right
hemispheredamaged patients, in comparison to left
hemispheredamaged patients, also have difficulty in naming the
emotions conveyed by different facial expressions [
Butchel et al., 1978
Mc Keever and Dixon, 1981 Natale et al., 1983
Left visual-field (right hemisphere) advantage
was found for the processing of all emotions
4. Lateralization in the expression of facial emotion: Experimental and clinical evidence
In expression studies, actors are required to produce
facial expressions in posed or spontaneous conditions.
In these studies, facial composites are prepared by
cutting the original and mirror-reversed prints of each
photograph along the vertical midline and then joining the
appropriate sides (e.g. [
]). The left-left (LL)
composite is thus produced by joining the left hemiface of
normal orientation and its mirror image. Similarly, the
right-right (RR) facial composite is prepared by
assembling the right hemiface of normal orientation and its
mirror image. Observers are asked to rate these
composite photographs in terms of intensity of expression
(see also [
Findings from these experiments suggest a left
hemifacial bias for both posed and spontaneous expressions
of emotion (See Table 2). A left hemifacial bias in
emotion expression presupposes the right hemispheric
involvement because of the crossed cortical dominance
by the way of contralateral fibre connections.
Metaanalyses also show compelling evidence for a left
hemiface bias, especially during negative emotion
expressions; the effect size is less pronounced for a right
hemiface bias for positive emotion expressions (see [
These findings have been substantiated with clinical
evidence examining the ability of patients with focal
brain damage to communicate emotions via the face.
In a review of these studies, Borod [
] found that
right hemisphere-damaged patients were significantly
more impaired than left hemisphere-damaged patients
for posed [
] and spontaneous [
facial expressions of emotion. Based on this evidence,
] conceptualized two hypotheses with
regard to hemispheric involvement in emotional
behavior: (a) a right-hemisphere hypothesis, and, (b) a
valence hypothesis. The first hypothesis proposes that the
right hemisphere is dominant for all kinds of emotions
(see also [
]). The second hypothesis assumes that
the right hemisphere is specialized for negative
emotions and the left hemisphere is specialized for positive
emotions (see also [
]). A variant of this hypothesis
assumes that the two hemispheres are differentially
specialized for the expression and experience of emotion
as a function of valence but not for the perception of
emotion. According to this view, the right hemisphere
is specialized for the perception of emotion irrespective
of valence (see also [
In sum, the evidence in favor of right-hemisphere
involvement in emotion perception and expression is
]. Bowers, Bauer, and
Heilman  reviewed evidence from neuropsychological
studies and concluded that the right hemisphere
contains a “vocabulary” of nonverbal affective signals
(facial expressions, prosody, and gestures), supporting the
notion of a general processor (rather than specific
processor for particular facial expressions, prosody, etc.)
for emotion processing in normal subjects [
But a role for the left hemisphere in the earliest level
of processing of facial emotions has not been ruled out.
] speculated that “(the) right hemisphere
lateralization for emotion may actually be due to a left
superiority for the inhibition of emotion” (p. 73).
Further, social perception depends on the ability to
dissociate signals from social and nonsocial situations. This
function may be mediated primarily by the left
hemisphere. Social situations embody both perceptual as
well as conceptual cues. Conceptual information has
been found to be mediated by the left hemisphere, and
perceptual information has been found to be mediated
by the right hemisphere [
The involvement of the right hemisphere in positive
affect states is also somewhat controversial. Some
investigators have demonstrated a bilateral advantage for
the processing of positive emotion whereas others have
documented a left-hemispheric advantage for the
processing of such emotions [
]. Researchers have also
speculated about a distinction in terms of motoric
direction as well as approach-withdrawal  in addition to
a positive-negative distinction within the emotion
categories. The roles of hedonic valence and motoric
direction were tested in a recent study on brain-damaged
]. Right hemisphere-damaged patients had
specific deficits relative to left hemisphere-damaged
patients in processing negative and withdrawal
emotions; there was a non-significant group difference for
The issue of posed vs. spontaneous expressions has
generated some controversy. Posed expressions are
produced voluntarily whereas spontaneous expressions
are produced automatically in response to an
affective situation. Anatomical evidence suggests different
anatomical involvement during these two situations;
for example, neocortical structures have been
implicated for posed expression and subcortical structures
for spontaneous expressions [?,95]. Though many
experimental findings suggest a left hemifacial bias for
both posed and spontaneous expressions of emotion,
some studies do not report a hemifacial bias for
spontaneous expressions (for example [
Finally, facial musculature is not solely controlled
by the contralateral mechanism of the brain (the right
hemisphere – the left side of the face). It has been
observed that the muscles in the lower region of the face
are contralaterally innervated by the fibre projection of
the two cerebral hemispheres [
]; however, the
facial nerves originating in the right hemisphere are
distributed uncrossed to the upper region of the face.
Supporting these obersvations, a recent study found
that the right upper face is more expressive than the left
upper face .
5. Universality and culture-specificity
Having examined the issues related to laterality and
emotion, we now turn to the question about the
innateness versus the cultural specificity of facial expressions
of emotion. Neurophysiologists, cultural
anthropologists, and psychologists have been addressing this
issue for several decades. Beginning with the influential
early work by Darwin [37,38] that favored universality,
researchers in psychology have spent decades
examining the issues of the universality and cultural specificity
of the expression, experience, and judgment of
emotion. Extreme positions taken by early theorists have
gradually given way to recent theoretical models with
an interactionist perspective that suggest a role for both
universality and cultural specificity (e.g. [
]). Proponents of this view consider
emotion as a composite of several subsystems that include:
(a) antecedent events, (b) emotional experience, (c)
appraisal, (d) physiological change, (e) change in action
readiness, (f) behavior, (g) change in cognitive
functioning and beliefs, and, (h) regulatory processes [
]. Each subsystem of a modal emotion may
vary as a result of variation in culture and, therefore,
it is essential that universality has to be examined for
each of these subsystems of an emotion before
generalizations can be made.
Ekman [43,44] suggested that facial emotions are
expressed in a universally similar manner. He
maintained that primary emotions are expressed by a
combination of facial muscular movements that are neurally
connected. Six primary emotions were identified with
distinct facial muscle combinations during expressions
happiness, sadness, fear, anger, surprise, and disgust.
Two lines of evidence are available to support Ekman’s
view, dealing with (a) the decoding (understanding)
of facial emotion, and, (b) the encoding (expression)
of facial emotion. Decoding studies require observers
of different cultures to judge the facial expression of
primary emotions, namely, happiness, sadness, fear,
anger, disgust, and surprise. Facial expressions of
emotion do seem to be recognized panculturally in Western
and non-Western cultures [
well as in literate and preliterate populations [
In comparison to decoding studies, attempts made to
test universality in the expressions of primary emotions
have been relatively less frequent. Encoding studies
require that the subjects of different cultures express
basic facial emotions. These emotions are produced
either by imagining affective situations, or by following
instructions to move facial muscles in a definite pattern.
Some data suggest that facial emotional expressions
are displayed by all cultures as long as socially learned
display rules do not interfere .
], on the other hand, has argued that
the recognition of facial expressions of emotion
depends to a large extent on the sender’s and receiver’s
language and culture (see also ). Reviewing the
cross-cultural evidence for the recognition of facial
expression of emotions, Russell concluded that “facial
expressions and emotion labels are probably
associated, but the association may vary with cultures and is
loose enough to be consistent with various alternative
accounts” [113, p. 102].
In examining the classic data on emotion
recognition along with newer cross-cultural evidence, a recent
meta-analysis has provided evidence for an “ingroup
advantage” in emotion recognition [50,51]. That is,
emotion recognition is more accurate when members of
the same cultural group that express the emotions also
make the judgments. This ingroup advantage has been
seen across a range of experimental methods and
nonverbal channels of communication, as well as across
each of the basic emotions, both positive and negative.
Further, the ingroup advantage has been found when
examining only balanced studies, in which members
of every cultural group in the study judged emotions
expressed by members of every other group. Such
balanced studies control for possible differences in the
main effects of emotional expression and recognition
ability across cultures, while examining the impact of
cultural match or mismatch on communication
accuracy in the form of an interaction effect. Thus, there is
strong evidence for an ingroup advantage in emotional
decoding even after controlling for absolute differences
The universality thesis argues that facial expressions
of emotion are uniformly understood, expressed or
experienced across cultures (for example ).
Opponents of this view (cultural relativism) suggest that,
despite universality, culture plays a major role in the
understanding and expression of facial emotion and that
emotion expressions are a natural outgrowth of cultural
]. Their argument is grounded in
ecological demand, ethnic variation, social construction
of the self, and cultural practices. These two extreme
views rarely acknowledge the fact that biological and
social signals may be accommodated in an opposite but
complementary manner in facial emotion research. To
understand this interface, contributions from
lateralization research can be utilized that suggest an asymmetry
of both the expression and the perception of facial
expression. We suggest that linking the judgment of facial
expression with findings on laterality might provide one
way to disentangle innate and culture-specific effects.
The laterality literature suggests that facial expressions
of emotion, though distinct and universal, are not
uniformly displayed or consensually judged. Asymmetry
in facial expressions of emotion may be produced as
a result of a variety of factors such as neurobiological
constraints as well as by cultural factors .
The bulk of the literature on laterality and facial
emotion reviewed earlier in this paper suggests that (a)
facial expressions of emotion are better perceived in the
left than in the right visual-field (a right-hemisphere
dominance) of the perceiver, and, (b) the left side of
the face, in comparison to the right, displays
emotion in a more pronounced manner (a right-hemisphere
dominance). With regard to the first proposition, that
emotion judgments are governed by right-hemisphere
dominance, some authors argue that the left
visualfield dominance is found generally for face recognition
rather than specifically for recognition of facial
emotion. Neuropsychological research has established that
the two processes (face recognition and recognition of
facial emotion) are separate. Prosopagnosic patients
(who do not recognize familiar faces following
damage to the visual system) retain the ability to
recognize facial expressions of emotion . Studies with
normal subjects have also documented a difference in
performance on face-identity judgment tasks and
faceemotion judgment tasks [
]. The second
proposition, that emotional displays are right-hemisphere
dominant, has also been criticized with the argument that
the left hemifacial dominance in emotion production
may be a function of non-emotional peripheral factors.
For example, if the two hemifaces differ in the degree
of muscular activity, the hemiface with greater
mobility might be perceived as more emotionally expressive.
But the role of the peripheral factors in the production
and judgment of neutral expression in comparison to
emotion expression is significantly reduced. Yet the
resting left hemiface is judged either more happy [
or miserable [
] than the right hemiface. In one study,
Mandal, Asthana, Madan, and Pandey [
the asymmetrical nature of the resting (neutral) face by
preparing hemifacial composites, left-left, right-right,
and a normal facial orientation. The left-side facial
composites were found to be more emotional than the
right-side or normal facial orientations of neutral
These two propositions suggest that in face-to-face
interactions the dominant side of the face does not fall
into the dominant visual-field of the perceiver. Other
researchers have also tested similar face-to-face
situations (for example [
]) and have examined the impact
of lateralization of facial expression on the attribution
of personality [
], and facial attractiveness [
instance, Asthana and Mandal [
] tested a speculation
that the mirror-reversal of a facial expression would be
perceived as more intense in comparison to its normal
orientation because in such a case the hemiface (left),
dominant for emotion expression, will be processed by
the side of a hemisphere (right) that determines
judgment about a whole face in a free-viewing condition.
As predicted, expressions in the mirror-reversed
orientation were perceived as more intense than those in the
normal orientation. Based on these findings, Asthana
& Mandal suggested two possibilities as to why the
emotional tone in the left hemiface eludes day-to-day
notice. First, “we learn in the course of human
development to civilize intense emotional expressions . . . by
the side of the face (right) which is more under the
voluntary motor control of the [left] cerebral hemisphere.”
Alternatively, “we evolve a strategy in the course of
civilization to process the emotionally pronounced side
of the face (left) by the hemisphere side (left) that
largely mediates cognitive ability. . . (p. 117)”. These
speculations were, however, made based on evidence
drawn under laboratory conditions. Further studies are
needed to substantiate these views with more recent
methodologies involving visual scan paths.
Taken together, these studies suggest that although
some components of facial emotion are more
biologically governed, others are moderated to great extent
by cultural experience. Undeniably, therefore, these
two components develop an interface to facilitate
social communication. Relatively less theoretical energy
has been expended to examine the reciprocal nature
of the biological and cultural components of facial
expressions of emotion. But the literature does provide
evidence upon which such a theory can be built. For
example, neuropsychological research has shown that
the two sides of the human face are not equally
expressive, and that ‘asymmetrical facial expressions have
some relationship to the functional asymmetry of the
]. The right side of a face (controlled by the
left hemisphere that primarily mediates cognitive
behavior) offers socially appropriate clues whereas its left
side (controlled by the right hemisphere that primarily
mediates emotional processes) divulges hidden
personalized feelings (see for example [
]). This proposition
was originally made by Wolff [
] who suggested that
the left side of the face expresses more personalized,
hidden and unconscious content while the right side of
face reveals more social, explicit and conscious
content of personality (see also [
]). Support for the
differential hemispheric involvement in facial
expression is drawn from both clinical as well as experimental
studies. Neuroanatomically, the left side of the face is
motorically governed by the right side of the brain (via
contralateral fibre connections), which is relatively
specialized for processing of emotions; the left side of the
brain, which is relatively specialized for cognitive
processing, governs the right side of face. Buck [
] also suggest that the right hemisphere is
associated with emotional processes and the left
hemisphere with the control (i.e., facilitation, inhibition) of
these processes as per the socially approved rules.
Given such evidence, one may argue that the left
in comparison to the right side of the face should be
more emotional, uninhibited and culture-specific.
Expressions of the right side of face, on the other hand,
should be pancultural, and should exhibit emotional
expressions in accordance with universal norms.
Universal expressions are expected to be displayed by the
right side of face due to greater voluntary motor control
which is contralaterally connected with the relatively
less emotional side of the cerebral hemisphere (left) for
the facility of social interaction [
Two recent studies were conducted that examined
this claim. In one study, hemifacial composite photos
(left-left, right-right, and normal orientation) of three
cultures - Japanese, Oriental Indian, and North
American - displaying six emotions happy, sad, fear, anger,
surprise, disgust, and a neutral state - were judged by
Indian observers for distinctiveness of expression. The
findings suggest that facial emotions were displayed in
a universal manner; however, there was a subtle
difference in the hemifacial involvement of expression.
Although North Americans showed left hemifacial bias
for all emotions, Japanese showed a right hemifacial
bias for positive and left hemifacial bias for negative
emotions. Negative emotional expressions were least
distinctly identifiable in Japanese faces, followed by
Indian and North American faces [
In another study, the in-group advantage in emotion
judgment was examined as a function of the
hemifacial differences in expressions. Participants from the
USA, India, and Japan judged facial expressions from
all three cultures in a balanced design. The right-right
facial composites, in comparison to the left-left
composites, yielded more cross-cultural agreement. More
specifically, the in-group advantage was greater for the
left-left than the right-right composites. These
findings suggest that the left side of the face has an
expressive style that is more culture-specific and less
These studies do not conclusively prove that the two
hemifaces differ as a function of the differential
influence of biology and culture. A host of factors may
influence facial asymmetry including anatomical,
neurological, psychological, pathological, and socio-cultural
]. More studies are needed to examine the
theory proposed above that control for variables such
as hemiface size, developmental changes, age, sex, etc.
Such studies will pave the way towards the
development of cross-cultural neuropsychology [
] in the
communication and experience of emotion. Cross-cultural
neuropsychology is an emerging discipline that
examines behavioral neuroscience within a cultural context.
Behavioral neuroscience explores the biological bases
of behavior by drawing from the fields of
neurospsychology, neurophysiology, psychopharmacology,
neuroanatomy and neuroendocrinology. Cultural
psychology, on the other hand, understands behavior from the
interdisciplinary perspectives of anthropology,
behavioral ecology and social and developmental
psychology. The interest in examining cultural issues in
cognitive neuropsychological performance has generated
a great deal of research, for example, the influence of
], literacy , socio-educational
], and cultural norms [
]; for details see
]. Very few attempts have been made,
nevertheless, to examine the relationship between culture
and the neuropsychology of emotion. We suggest that
examining laterality effects in cross-cultural studies of
facial expressions of emotion will advance our
understanding of both the communication and the
construction of emotion.
Preparation of this article was supported by a
Fulbright Visiting Lecturer Grant to MKM at Harvard
University, USA to the first author and a NSF
Presidential Early Career Award to the second author.
Correspondence concerning this article may be addressed to
Manas K. Mandal, Department of Humanities and
Social Sciences, Indian Institute of Technology –
Kharagpur – 721302, India. The authors thankfully
acknowledge the help of Hari O. Sharma in preparation of this
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