Cultural Differences
Running head: CULTURAL DIFFERENCES IN PAIN EXPRESSION
Cultural Differences in Pain Expression in a Cold Pressor Task
Nancy Alvarado
California State Polytechnic University, Pomona
Ralph B. Jester
University of California, Irvine
Christine R. Harris
University of California, San Diego
Julia F. Whitaker
University of Utah, Health Sciences Center
Author Contact:
Nancy Alvarado, Ph.D.
Department of Psychology and Sociology
California State Polytechnic University
3800 W. Temple Ave.
Pomona, CA 91768
Phone: (909) 869-3896
Email: nalvarado@csupomona.edu
Key words: acute pain; pain assessment; racial and ethnic differences; under-treatment of pain,
cold pressor, pain facial expression
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Cultural Differences
Abstract
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Cultural Differences
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Cultural Differences in Pain Expression in a Cold Pressor Task
Numerous studies have documented that members of ethnic and racial minority groups,
and women, are more likely to be under-treated for pain (Bonham, 2001; Weisse, Sorum &
Dominguez, 2003; Hoffman & Tarzian, 2001). Under-treatment has been reported in emergency
treatment of bone fractures (Todd, Deaton, D’Adamo, & Goe, 2000; Todd, Samaroo & Hoffman,
1993), cancer pain (Cleeland, Gonin, Baez, Loehrer & Pandya, 1997; Cleeland, Gonin, Hatfield,
Edmonson, Blum, Stewart & Pandya, 1994), and postsurgical care (McDonald, 1994). Further,
even when treated, they are less likely to be given stronger opioid drugs (Pletcher, Kertesz, Cohn
& Gonzales, 2008). Williams (2002; Kappesser & Williams, 2002; Kappesser, Williams &
Prkachin, 2007) suggested that this under-treatment may arise from physician bias, a tendency to
underestimate a person’s pain and thus under-prescribe pain medication, or even misdiagnose the
underlying condition. Prkachin (Prkachin, Berzins & Mercer, 1994; Prkachin, Mass & Mercer,
2004; Prkachin, Solomon, Hwang & Mercer, 2001) documented a systematic underestimation of
pain that was greater among experienced health care providers than untrained observers. He and
his colleagues demonstrated that the actual facial movements of a pain expression increased with
greater self-reported pain, providing a read-out that was accurate at high intensities of pain, less
so at lower intensities. However, despite this perceptual information, physicians displayed an
underestimation bias when physician pain ratings were compared to sufferer pain ratings on the
same rating scale. This suggests that physicians may observe pain expressions but discount them,
placing less reliance on them than untrained observers do. In this research, we explored reasons
for the observed under-treatment of pain and accompanying physician underestimation bias.
Specifically, we investigated whether members of racial and ethnic minority groups (here called
subcultures) were likely to show differences in their pain expressivity, self-report or physiology
that might be misinterpreted by physicians and result in under-treatment for pain.
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The tradeoffs between detection of malingering and accurate appraisal of pain may
contribute to physician underestimation bias (Williams, 2002). When physicians become too
suspicious, their failure to accurately assess pain may contribute to a vicious circle in which
chronic pain sufferers exaggerate their pain in order to be adequately treated while physicians
respond to the exaggeration by increasingly discounting their expressions of pain. Studies of
chronic pain sufferers suggest that individuals may over time exaggerate their expressions in
order to more effectively communicate with health care deliverers, even showing pain
expressions when no pain is felt (Prkachin, Berzins & Mercer, 1994; Prkachin, 2005). Chronic
pain sufferers are most often suspected of malingering (Mendelson & Mendelson, 2004).
Historically, physicians have been suspicious of higher pain reports. Mendelson & Mendelson
(2004) review historical attitudes toward malingering. They cite Hackett (1971), who described a
prejudiced physician attitude toward patients in pain, and Miller & Cartlidge (1974) who defined
malingering as not only simulation of disease or disability not present, but also, a much more
frequent gross exaggeration of minor disability. Mendelson & Mendelson (2004) stated, “Given
the subjective nature of pain, it therefore becomes problematic to determine what would be the
“expected” extent of pain associated with a particular physical lesion…” (p. 425). Physicians are
reported to become less sympathetic, even angry, if they believe that patients are exaggerating
their pain symptoms or reports (Poole & Craig, 1992; Prkachin & Craig, 1995). Keefe &
Dunsmore (1992) noted, “Conscious efforts to communicate pain through guarded movements,
facial expressions, or extreme ratings of pain upset and even enrage clinicians.” (p. 97, quoted by
Prkachin & Craig, 1995, p. 202).
Thus, difficulties can arise for members of minority subcultures if their experience of
pain is divergent from that of the majority of patients, or if their expressivity is different. Such
differences may lead physicians to suspect dissimulation and give rise to discounting of self
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report or facial expression or even suspicion of malingering. The actual experience of pain
among minority group members is not as well studied as among non-minorities. For example,
opioid-induced hyperalgesia (a greater sensitivity to pain-inducing experience) may be expected
to affect minority group members differentially if their exposure to such drugs differs from that
of other groups. Recent investigations suggest that real differences exist in pain experiences
among African American; Hispanics, and Asians (Lipton & Marbach, 1984; Edwards &
Fillingim, 1999; Breitbart & McDonald, 1996; Sheffield, Biles, Orom, Maixner & Sheps, 2000;
Bates, Edwards & Anderson, 1993; Brena, Sanders & Motoyama, 1990; McCracken, Matthews,
Tang & Cuba, 2001; Weisenberg, Kreindler, Schacht & Werboff, 1975; Barak, Weisenberg,
1988; Faucett, Gordon & Levine, 1994; Sternbach & Tursky, 1965). Greater awareness of sex
differences in pain experience has led to a consequent correction in physician expectations
(Weisse, Sorum & Dominguez, 2003). Differences in emotional response to clinical situations,
including pain-related anxiety, have also been documented in African American patients
(Fillingim, Edwards, & Doleys, 2002; McCracken, Matthews, Tang & Cuba, 2001). These
studies suggest that increased ratings of pain can result from an increased experience of pain, not
solely from a tendency to describe pain differently or to use rating scales differently.
Stereotypes about the expression of pain complicate actual differences in pain experience
and report. Early research in pain expression had no method for objectively and systematically
describing facial action, as now exists with Ekman and Friesen’s Facial Action Coding System
(FACS) (1978). As with early research on emotional expressions, studies of pain expression were
often impressionistic rather than scientific. Studies of “Yankee” (Northeastern American) and
Jewish subgroups (Tursky & Sternbach, 1967; Sternbach & Tursky, 1965) contributed to today’s
general belief that ethnic groups may have characteristic styles of pain expression. Yankees were
considered stoic whereas Mediterranean people were described as “dramatic.” With the advent of
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better methods for characterizing facial activity, the issue of styles or dialects of expression can
be more rigorously addressed. For example, Asians are stereotypically thought to be more stoic
than European-Americans (Chang, 2003). Recent attempts to study this using infant facial
expression showed mixed results for Japanese and Chinese or Chinese-Canadian infants
compared to non-Asian infants (Rosmus et al., 2000). Further, it is unclear whether culture can
strongly modify facial expression. Learning-based models of facial expressivity attribute cultural
differences to socialization, yet attempts to modify facial expression were unsuccessful for adults
modeling tolerance and intolerance of pain (Craig & Patrick, 1985). A conflicting study in which
mothers modeled pain behavior to their children (Goodman & McGrath, 2003) confounded
heritability with modeling. More recently, the ability to both enhance and suppress expression
has been associated with successful coping with adversity (Bonanno et al., 2004). As with many
characteristics, larger variability in expressivity exists within a cultural group than between
groups (Prkachin, 1992; Prkachin & Craig, 1995).
Whether cultural differences in expression exist or not, wide individual variability
implies that an entirely genuine pain response may be inappropriately treated if the physician
holds mistaken expectations about the amount of pain a patient should be expressing. A mistaken
expectation may arise from a misunderstanding of real differences in pain experience coupled
with triggered stereotypic beliefs about minority pain. To complicate matters, stereotypes differ
for males and females due to different gender roles in some subcultures. For example, Hispanic
patients are stereotypically judged as histrionic or overly expressive, especially when female. An
expressive Hispanic man may be judged as malingering because his expressions are inconsistent
with expectations about macho stoicism. Or he, himself, may conceal and under-rate his own
pain because he considers it unmanly to reveal pain. African-American and Asian stereotypes
have historically included insensitivity to pain as part of the justification for mistreatment during
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enslavement or “Coolie” indentured servitude (Chang, 2003). Such stereotype-driven
expectations conflict with the observed greater sensitivity to pain reviewed above. Physician
attitudes about malingering or misuse of emergency room services by immigrant groups such as
Hispanics and Asians with low socioeconomic status may contribute to resentment and lessened
sympathy among physicians. Further, immigrant patients may believe that the way to be a “good
patient” is to suffer without complaint, leading to misdiagnosis or under-treatment.
Studies of pain deception show that adults and children can more readily exaggerate than
suppress pain facial expressions (Poole & Craig, 1992; Larochette, Chambers & Craig, 2006).
When there is a discrepancy between self-report of pain and facial expression, physicians give
greater credence to the facial expression (Prkachin & Craig, 1995; Poole & Craig, 1992). They
believe that self-reports are easier to fake than facial expressions. This reliance on facial
expression is problematic because of the large individual differences in expressivity. Prkachin &
Craig report “At severities at which the pain was reported to be substantial, 13-50% of subjects
displayed no facial evidence.” (p. 194; Wilkie, 1995). How are facially inexpressive patients who
self-report strong pain treated when they are members of an ethnic minority? It seems likely that
there is a difference in the potential for under-treatment when inexpressivity is stereotypecongruent rather than stereotype-incongruent. These questions have not been investigated.
In the face of such complexities, it would be useful to identify a “gold standard” for
assessment of pain. Pain is typically assessed using multiple indicators, including physical
responses such as tachycardia, blood pressure reactivity, muscle rigidity, and behavioral
measures such as self-report (verbal and “Oucher” or “Face” scales), guarding, and facial
expression (Jensen & Karoly, 2001). However, use of indicators such as tachycardia and blood
pressure reactivity is frequently prevented by advanced age, hypertension (which is antinociceptive), beta blocking or hypertension medication, or presence of narcotics, leaving the
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physician reliant on facial expression and self-report. Self-report is given strong weight except
where patients are suspected of medication seeking or malingering (McCaffery, 1979; Mersky,
1979), but Poole & Craig (1992) note that self-report is affected by situational factors and
incentives. Further, self-report may be unreliable when patients are infants, children or elderly,
when conscious introspection is impaired, or when patients cannot speak or communicate
effectively, increasing reliance on facial expression of pain. Further, self-report scales are subject
to a variety of anchoring, retrospective and other scale biases, only now being investigated. Some
researchers suggest that under-treatment of pain might be reduced if facial expression were
preferred to other indicators (Williams, 2002; Prkachin, 2007).
Accurate estimation of pain may be accomplished using facial expression, but only if
physicians use the cues actually present in the face instead of relying upon beliefs about pain
(Prkachin, Berzins & Mercer, 1994). Poole & Craig (1992) demonstrated that observers tended to
give more weight to a person’s pain facial expression than to their pain statements, even when
the expressions were faked or suppressed and thus inaccurate. Hill & Craig (2004) suggested that
individuals can be trained with feedback to more accurately assess pain facial expressions,
whereas information-based training was unhelpful. Unfortunately, many individuals are facially
inexpressive or show incongruence between facial expression and other pain indicators, making
the use of facial expression as a gold standard problematic for many sufferers.
Although physicians routinely deal with pain, they may not be pain experts. Because
assessment of pain is generally a holistic judgment with several inputs, physicians may be
unaware of the extent to which their own cultural stereotypes and beliefs can affect their
interpretation of pain indicators. As Prkachin & Craig (1995) noted, even when beliefs about
pain are explicit, “Stereotypes fail to recognize tremendous within-group differences and small
between-group differences that call into question their utility.” (p. 198). Thus, understanding the
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nature of real and assumed differences among groups is crucial to: (a) accurate interpretation of
pain self-report and facial expression; and (b) accurate identification of medication-seeking,
malingering and other deception. Optimal treatment for members of minority subcultures relies
upon accurate estimation of pain whichever indicators are used.
This research used multiple measures to assess pain expressivity on a cold pressor task
across four subcultures within the student population: (1) African Americans; (2) Asian
Americans and Asian immigrants; (3) Hispanic; and (4) European Americans. The dependent
variables included: (1) autonomic measures; (2) facial expressivity; (3) self report using several
types of scales; (4) measurement of pain attitudes by questionnaire; and (5) measurement of
acculturation by questionnaire. Our goal was to examine similarities and differences on these
measures across the four groups, to examine coherence among the measures within groups, and
to identify any differences that might be linked to stereotypes or the systematic under-treatment
among physicians and other health care professionals. We predicted that cultural beliefs would
mediate pain expressivity (facial expression) and self report and that we would find greater
stoicism within the Hispanic and Asian groups and greater expressivity among African
Americans. We further predicted that women would be more expressive than men, based on their
greater expressivity in other facial expression studies and the greater acceptance of complaint
about physical discomfort permitted of women within many cultures. Specific hypotheses are
noted where appropriate in the Results section.
Method
Participants
Our intention in this study was to recruit students in order to limit prior experience and
increase the likelihood of finding healthy subjects without chronic pain or drug use. Participants
are listed in Table 1 by sex and ethnicity. All subjects were students at the California State
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Polytechnic University, Pomona, ranging in age from 18 to 53 (mean = 22.1, sd = 4.0). Subjects
were included in the data analysis only if they had complete data on all measures. Most subjects
were recruited using an online human subjects pool signup system and were given course credit.
Due to difficulty recruiting sufficient participants via the subject pool, some African American
and Asian American male subjects were recruited from campus locations via flyers and were paid
$10 for their participation. Subjects were screened for health problems that might interfere with
their ability to experience pain or produce facial expressions (e.g., high blood pressure,
schizophrenia or depression). Individuals currently taking pain medication or medications that
might alter autonomic response were also excluded.
Materials
The cold pressor task was administered using a Jeio Tech RW-0525G refrigerated
circulating bath which maintained water temperature at 3o Centigrade within two tenths of a
degree. A Biopac MP100WS psychophysiological recording system was used to record heart
rate, blood pressure and electrodermal activity. A Vasotrac system was used to continuously
measure blood pressure via a wrist cuff. A Sony 900 digital video camera was used to record
facial expressivity during a 10 minute baseline and throughout the cold pressor task.
To assess pain attitudes, a review of the literature on cultural beliefs about pain was
conducted. This resulted in a series of questions that were presented to four focus groups, asking
subjects about their family attitudes and beliefs about pain. From this, an exploratory pain
attitudes questionnaire was developed, consisting of 63 questions assessing different aspects of
belief about pain and its appropriate expression. A more detailed description of the focus group
and questionnaire results is reported by Englert, Jester, Alvarado, Harris and Whitaker (2009).
Self-report rating scales included a series of seven-point scales anchored by emotion
terms, the McGill Pain Inventory, and a seven-point pain rating scale. Acculturation was
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measured using an inventory appropriate to each subject’s self-described cultural background.
For Asian Americans, we presented the SL-ASIA (Suinn, Rickard-Figueroa, Lew, & Vigil,
1987). For Hispanics, we presented the Short Acculturation Scale for Hispanics (Marin, Sabogal,
Marin, Otero-Sabogal & Perez-Stable, 1987). For African Americans, we presented the revised
African-American Acculturation Scale AAAS-R (Klonoff & Landrine, 2000). FIX Two scales
were used to assess African American acculturation, one based on adherence to cultural practices
within the African American subculture, the other based on attitudes toward European
Americans. The European American scale was the counterpart to the latter and largely concerned
attitudes toward African Americans. The Hispanic and Asian American acculturation scales were
largely based on languages spoken and participation in activities within the subculture.
Procedures
After informed consent and screening for inclusion, subjects were asked to wash their
hands and remove any jewelry or watches. They then were seated inside a cubicle in a chair
facing a screened video camera (to minimize its salience) while an experimenter affixed sensors
to monitor heart rate at ankles and wrist. The Vasotrac wrist cuff and a finger sensor for
electrodermal activity were attached. Following that, the subject was left alone for a 10 min
videorecorded baseline period to permit the subject to accustomed used to the camera and
presence of the sensors. The experimenter then returned. A doorbell-type signal was placed in the
participant’s right hand and the experimenter asked the subject to press it, to demonstrate its
operation. The subject was instructed to press the signal button at the first sign of pain and again
when the pain became intolerable and they wished to remove the hand from the water. Subjects
were asked to tolerate the water as long as possible, but were also told they could remove the
hand whenever they wished. The experimenter left the cubicle and from outside told the subject
to “go” (start the task) by placing his or her hand in the cold water up to the wrist, with fingers
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open but not touching the sides or bottom of the tank. The experimenter was seated behind a
screen outside the cubicle and recorded the start, first signal and second signal on the Biopac
record. When the signal button was pressed for the second time (or the subject removed the
hand), the experimenter returned and dried the hand with a towel. If the subject did not press the
second button by the end of 3 minutes, the experimenter returned and ended the task.
Immediately following the task, the subject was asked to complete the McGill Inventory on a
clipboard and rate the pain. Following that, the subject was moved to a computer to complete the
other rating scales and inventories. Pain and emotion ratings were presented first, followed by the
pain attitudes questionnaire and then the acculturation questionnaire, followed by a debriefing. If
the subject tolerated the pain for 3 minutes (timed out), the experimenter asked follow up
questions about that during the debriefing.
Results
Cold Threshold and Tolerance
The cold threshold was measured as the time from first immersion in cold water to the
time the signal button was pressed for the first time, to signal the experience of pain. Cold
tolerance was measured as the time from the first button press to signal pain until the second
button press to request removal of the hand from the water. A time-out was recorded when the
subject left the hand in the water for 3 minutes, at which time the hand was removed by the
experimenter. No significant differences were found across the four subcultures for threshold,
tolerance, or total time in water. However, 12 timeouts were observed in the European American
group compared to 6 for Asian American and 4 for the other groups, which contributed to a
nearly significant difference in total time in water, F(3,179)=2.126, p=.099, but did not affect
tolerance or threshold. Examining the debriefing responses, this higher number of timeouts
appeared to be related to the number of athletes in the European American group. They reported
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surfing and swimming in cold water or using cold water hydrotherapy to treat sports injuries.
They may also have been more likely to regard the pain manipulation as a challenge or
competition. With all timeouts removed, there was no significant difference in mean pain
threshold, tolerance or total time in water across groups. A consistent sex difference was found
for threshold, t(181)=4.188, p=.000 and total time in water, F(1,155)=7.715, p=.006, but no
significant difference was found for tolerance, t(181)=1.265, p=.207.
Biophysiological Measures
Physiological measures were used for two purposes: (1) to verify that participants
experienced pain during the cold pressor task; and (2) to determine whether any group showed
significant differences in physiological response. Christine please add results here
Pain and Emotion Ratings
Participants rated pain and a series of emotions using seven-point rating scales, including:
happiness, anger, fear, anxiety, frustration, embarrassment, calmness, sadness and surprise. No
significant differences were found across the four subcultures on any of these scales (p < .05).
Significant gender differences for happiness, excitement, pain and embarrassment were found
(see Table 2). When ratings were normalized within sex, no significant differences were found
across subcultures. Similarly, when ratings were normalized within subculture, no significant
differences were found by group, but the sex differences remained significant. Although no other
significant differences were found after normalization, a trend was observed in which Asian
American participants showed smaller sex differences in their ratings compared to the other
three groups, while Hispanic and African American groups showed consistently larger sex
differences, suggesting that sex roles affected ratings more for those groups than for Asian
Americans and to a lesser extent, European Americans, as illustrated in Figure 2.
Participants also rated the quality of their experience using the McGill Pain Inventory. It
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includes rating scales anchored by a series of descriptive terms including: throbbing, shooting,
stabbing, sharp, cramping, gnawing, hot or burning, aching, heavy, tender, splitting, exhausting,
tiring, sickening, punishing, cruel, fearful and painful. The inventory is scored by combining
subsets of these scales to produce a sensory subscale and an affective subscale. Significant
differences were found on the sensory subscale, by group, with African American and Hispanic
participants of both sexes reporting higher scores, F(3,159)=2.878, p=.038. Significant
differences were also found by gender, with female participants consistently reporting higher
scores than males, F(1,159)=12.399, p=.001. There was no significant interaction between sex
and ethnicity, F(3,159)=.403, p=.751. For the affective subscale, no significant main effects were
found, but a significant interaction between gender and subculture was found, F(3,172)=2.958,
p=.034. This occurred because Asian American and European American female participants gave
higher ratings than males whereas Hispanic and African American males gave higher ratings than
females. Thus the pattern of results for the sensory subscale was considerably different than the
affective subscale, as shown in Figure 3.
In medical contexts, patients are frequently asked to estimate the amount of pain they are
willing to withstand using a ten-point scale. Our participants were asked to do the same. After the
pain manipulation, they then rated their pain using the same ten-point scale, permitting a
comparison of the anticipated and actual experience. The scale, as in medical contexts, was
labeled discomfort. The estimates were significantly correlated with the experienced discomfort,
r=.50, p=.000 but there was a significant difference between the estimated and experienced
ratings, F(1,137)=8.413, p=.005. All participants tended to overestimate the amount of
“discomfort” they would be willing to withstand. There were no significant differences between
subcultures and no significant interactions. There was a significant sex difference, with males
producing higher estimates than females and a greater discrepancy between their estimated and
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actual ratings, F(1,137)=14.107, p=.000. Ratings by sex and subculture are compared in Figure 4.
Interestingly, both the discomfort estimates and the actual discomfort ratings are uncorrelated
with the ratings made using a scale labeled “pain” immediately after the task, r=-.095 for
estimated discomfort and r=-.003 for actual discomfort.
Pain Attitudes Questionnaire
Although space does not permit a detailed analysis of the responses to the Pain Attitudes
questionnaire developed for this study (see Englert et al., 2009), an analysis of the responses for
each question showed that seven questions produced significant differences across groups. These
are listed in Table 2. To determine whether culture affected responding, a discriminant analysis
was used to classify subjects into subcultures based upon their questionnaire responses. Because
the group sizes were unequal, prior probabilities were computed from the group sizes during the
analysis. Those who had timed out were excluded. The discriminant analysis classified
participants into their self-identified subcultures with 81.1% accuracy. When sex was used as the
grouping variable, subjects were classified with 86.7% accuracy. To explore the impact of
culture on responses, subjects were divided into high and low acculturation groups using a
median split of their acculturation inventory scores. Those with high acculturation scores were
considered to be closer to the mainstream culture and those with low scores were considered to
be closer to their subculture. The discriminant analysis was then run again on each of these two
subsets of participants. The two separate groups of subjects classified by acculturation both were
correctly classified with 98.6% accuracy, however, the groupings are tightly clustered (more
cohesive) for the less acculturated subjects, as can be seen in Figure 5a. The improvement of
classification accuracy when acculturation is used to partition the sample demonstrates that
cultural attitudes toward pain do differ in ways that characterize each group. The questions that
were most important as discriminators are generally those that produced significant differences
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between scores (see Table 2). However, in addition to the items in Table 2, the following
questions were important to the discriminant analysis: (1) People who have suffered great pain
are to be admired; (2) I avoid the doctor because I am concerned that they might find something
truly wrong with me; and (3) There is no point to complaining when in pain. These questions had
significance levels of .07 using one-way ANOVA. Overall, groups differed along dimensions of
expressivity and stoicism, with Asian Americans reporting the least expressivity and the most
stoicism, and African Americans showing the greatest expressivity and the strongest belief that
pain is important during medical treatment (see Table 2).
Facial Expression
Facial activity during a ten minute baseline and during the cold pressor task was
videorecorded. Facial expressions were coded during the entire duration of the cold pressor task.
A comparable baseline period of equal duration was also coded, immediately before the end of
the baseline during the time when the subject was assumed to be most accustomed to the
presence of the camera. Ekman and Friesen’s (1978) Facial Action Coding System (FACS) was
used to identify facial movements associated with pain in previous research. These movements,
called action units (AUs) were compared in two ways: (1) mean number of each AU per subject;
and (2) number of subjects showing the presence or absence of each specific AU. Overall facial
activity was also measured by coding the number of events (co-occurring patterns of facial
activity) per subject (Ekman & Rosenberg, 1997). Representative pain expressions are shown in
Figure 6. No differences across groups were found for the AUs most frequently associated with
pain (e.g., AU 20, 9, 4+7, Craig & Patrick, 1985). No differences in the mean number of events
were found across groups, F(3,173)=0.66, p=.580 or by sex, F(1,173)=2.56, p=.110, suggesting
similar levels of expressivity. A discriminant analysis using all AUs as input variables correctly
classified subject by group with 45.3% accuracy (25% is chance) and by sex with 71.3%
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accuracy (50% is chance). Further analysis showed that AUs related to affect, not pain, accounted
for group differences, with an interaction between sex and subcultural group. While the results
were not significant, African American women were more likely to show AU 1+4 (characterized
as a distress expression), Hispanic and African American women were more likely to smile when
in pain (AU 1+6), and Hispanic men were more likely to frown (AU 4+7). The frequency of
smiling during pain was higher for women than men, F(1,173)=3.893, p=.050. Rates of smiling
and frowning by group are shown in Figure 7. As can be seen, Hispanic males and females
showed the greatest sex difference in expressive behavior, while Asian American males and
females showed the greatest similarity. There was a slight, nonsignificant trend toward less
expressivity for Asian American subjects across all types of AUs. No significant gender/ethnicity
interactions were found.
Discussion
The multiple measures used in our study present a complex picture in which some
measures show significant differences while others do not, but a pattern emerges. The high
acculturation of our college student sample may have prevented finding strong cultural
differences that may exist in more isolated communities and older immigrant groups.
Nevertheless, we found significant differences related to culture in the attitudes and beliefs about
pain and in the self-report and expressive behavior related to affect but not pain. No
physiological differences were found across subcultures, suggesting that the pain experience was
similar from a physical standpoint but different emotionally.
Based on our physiological measures, we are confident that our subjects experienced
strong pain. Excluding the timeouts which occurred when subjects approached the time-limited
cold pressor task as a competitive exercise, no group appeared more or less willing to tolerate
pain and thresholds for feeling pain were the same across groups. We did find the sex differences
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noted in previous studies, present within each of our cultural groups. The cultural differences
observed were found in facial expression related to affect (smiling, frowning, distress), as
classified by Ekman and Friesen (1978). The significant differences across subcultures were also
found in the self report of emotional states (happiness, embarrassment, anger) and in the McGill
affective subscale (not the sensory subscale). We found significant differences in attitudes and
beliefs about pain, largely along dimensions related to expressivity, expectations for physicians,
and the value of stoicism.
We found some support for the stereotype that Asian American are more stoic, but
believe this is related to attitudes and cultural norms about expressing pain. Asian subjects did
not choose swearing as an appropriate expression of pain for anyone (e.g., self, mother, father),
although all three other groups did. They were the only group to select “shake it off” as a
mother’s response to a cut hand. Although the difference was not significant, Asian American
subjects were consistently the least expressive facially (see Figure 7). Asian American subjects
were more likely to disagree that pain should be important to physicians and less likely to expect
pain treatment (see Table 2). Sex differences in the use of pain and affect ratings scales were
smallest for Asian American subjects.
In contrast, African American subjects seemed to value pain expression more and were
more expressive during the task. They agreed most strongly with the importance of physicians
treating pain, were more likely to express pain even in contexts where a job might be lost, and
tended to rate pain higher using the rating scales. They also showed more facial expressivity,
although this was a non-significant difference. African American women showed more frequent
distress expressions (AU 1+4) than any other group. African American subjects were more likely
to expect pain relief as part of medical treatment, despite also stating that doctors were more
likely to suspect them of medication seeking.
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Hispanic subjects showed large sex differences, both in rating scale usage (see Figure 3)
and in facial expressivity (see Figure 7). This suggests that culture-related gender roles may
dictate differences reflected in expectations and behavior for Hispanic subjects. The impact of
stereotypes about machismo did not produce suppression of expression, as expected. Instead,
there appeared to be suppression of positive affect and greater frowning, rather than in greater
stoicism overall. Hispanic subjects were nearly as expressive as African Americans and more
expressive than European Americans. There was no observed tendency to tolerate pain longer or
to rate pain as less severe, as might be expected given macho stereotypes. There may have been a
tendency to exaggerate pain, perhaps to compensate for inability to withstand the cold for as long
as desired. Greater embarrassment was reported for Hispanic and African American males,
perhaps related to their failure to tolerate the cold for the entire three minutes.
Although the difference was not significant, we observed that Hispanic and African
American women were more likely to smile when in pain. Smiling may be related to
embarrassment or shame, emotions that may arise in medical settings (Miller, 1996; Harris,
2006). This is important because physicians may believe that someone who is in pain would not
smile and thus discount their self-reported intensity of pain. Women are also an undertreated
group (Weisse, Sorum & Dominguez, 2003) and it may be that the increased smiling among
women in general, and minority women in particular, may account for much of the observed
under-treatment. This would not account for the under-treatment among Asian patients reported
in the literature, but it may be that different explanations apply to different groups.
The presence of smiling while in pain by both males and females during this task was
unexpected. Such smiling may be related to embarrassment or shame, emotions that may arise in
medical settings. In particular, males seemed to smile right before removing their hands from the
water, perhaps as an acknowledgement that they had to give up (Keltner, 1995). Smiling may be
Cultural Differences
20
a coping mechanism when feeling embarrassment or shame (Keltner & Anderson, 2000; Keltner
& Buswell, 1997). Subjects were seated alone in a cubicle during the cold pressor manipulation
to minimize social interaction, so they were not smiling at anyone or in supplication at any
person. If physicians believe that smiling always indicates pleasure or the absence of pain, this is
a serious misunderstanding of the nature of pain expression.
Several factors worked against finding significant differences across groups. First, we
kept water temperature at 3o centigrade. Lower water temperature tends to reduce sex differences
(CITE) by making it more difficult to tolerate pain in service of other goals. We believe that may
have impacted cultural self-expectations in similar ways. Second, although diverse, our subjects
are well-acculturated and many are psychology majors. They have been well-educated about
culture and gender roles and that may have influenced their responses. The differences observed
in this study are most likely the hardiest remaining after socialization into the mainstream
culture. We would predict that greater differences would be observed in studies of less
acculturated samples. Even so, attitudes and beliefs about pain were sufficiently different that
subjects could be classified by their responses into cultural groups with high accuracy. That
suggests that culture is an important mediator of pain experience and behavior in medical
settings. Beliefs and attitudes do influence emotional response and it is well known that emotion,
in turn, influences pain experience. If the strongest impact of culture is on emotion rather than
pain, it is still important to address such differences in medical practice.
Our findings suggest that it would be worthwhile for physicians to take into account
cultural differences when assessing pain. African American patients may be more expressive as a
group, without being suspected of intentionally exaggerating their behavior. Asian American
patients may be less expressive while feeling stronger pain than would be indicated by the same
behavior in someone from a different culture. Hispanic males may frown when in pain while
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21
Hispanic females may smile and show little negative affect despite pain. European Americans are
more likely to tell you about their pain. Because cultural differences appeared to have less impact
on pain expression (grimacing, nose wrinkling, eye tightening), it may be worthwhile for
physicians to learn to attend to these independent of affective expression (smiling, frowning).
Finally, the 10-point discomfort scale used by many hospitals showed little relation to the various
pain ratings and facial expressions in our study. All groups tended to overestimate the amount of
pain they were willing to tolerate, with greater accuracy for females than males. More seriously,
subjects tended to interpret the label “discomfort” to mean something different than “pain.” If
physicians are using the term discomfort as a synonym for pain our results suggest there may be
serious miscommunication.
The need for improved pain assessment is especially pressing today as the Joint
Commission on Accreditation of Healthcare Organizations (2000) has called for the monitoring
of pain as a fifth vital sign and made effective pain control part of hospital accreditation
standards. Consideration of these, and similar, cultural influences on pain expression can and
should be incorporated into physician training to improve accuracy of pain assessment.
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22
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Author Notes
Send correspondence to: Nancy Alvarado, Department of Psychology and Sociology,
California State Polytechnic University, Pomona, 3801 W. Temple Avenue, Pomona, CA 91768.
We thank Phyllis Ann Englert, Noriko Coburn, Yvonne Burgos, Ruben Hoyos, and the many
undergraduate students who assisted with this research. This research was supported by NIH
MBRS/Score Grant S06 GM053933.
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Table 1. Participants included in data analysis.
Female
Male
Total
African American
17
15
32
Asian American
25
25
50
European American
22
26
48
Hispanic
29
24
53
All Groups
93
90
183
29
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Table 2. Pain Attitudes Questionnaire items showing significant differences across subcultures.
Item
African
Asian
American
American
Hispanic
European
F or 2
p
American
If you were walking and you
3.69
4.42
3.68
3.92
came across a person who
(1.36)
(1.47)
(1.60)
(1.22)
2.80
.041
had just bumped into a very
sharp object, and they
showed no reaction at all,
what would you think of
them? (1=disapprove,
7=approve)
If your mother cut her hand
Bandage it Bandage it Bandage
Bandage it 51.83
while working around the
and go
and go
it and go
and go
house, what would she be
back to
back to
back to
back to
most likely to do?
work,
work,
work,
work,
scream or
scream or
swear,
swear,
yell, tell
yell, shake
scream or scream or
you how
it off
yell, cry,
yell, tell
much it
ask for
you how
hurt
help
much it
.042
hurt
I expect the doctor to listen
6.66 (.70)
to me when I talk about my
5.96
6.5 (.98)
6.23 (.99)
4.04
.008
2.90
.036
6.04
.001
(1.18)
pain. (1=disagree, 7=agree)
Pain relief is a major part of
5.59
4.74
5.25
4.94
medical treatment.
(1.29)
(1.59)
(1.29)
(1.31)
Doctors assume that
2.91
2.08
2.42
1.58 (.90)
everyone from my ethnic
(1.63)
(1.32)
(1.77)
(1=disagree, 7=agree)
background is seeking pain
medicine to sell on the
street. (1=disagree, 7=agree)
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There is a difference
6.03 (.97)
between being in pain and
5.46
5.79
5.25
(1.30)
(1.20)
(1.30)
31
3.33
.021
2.77
.043
being injured. (1=disagree,
7=agree)
I do not tell others when I
2.69
3.30
2.62
3.37
am in pain because I might
(1.64)
(1.75)
(1.48)
(1.63)
lose my job or my place on
an athletic team.
(1=disagree, 7=agree)
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Figure Captions
Figure 1. Pain experience results (total time in water with timeouts excluded) showed no
difference by ethnicity but a consistent sex difference for all four groups.
Figure 2. Standardized self-report ratings within subculture show that African American and
Hispanic males report greater embarrassment during the cold pressor task.
Figure 3. McGill ratings showed a different pattern of results for the sensory and affective
subscales.
Figure 4. Males and females in all four groups predict they can withstand more discomfort than
they are willing to tolerate.
Figure 5. Less acculturated subjects (top) are more readily classified by subculture based on their
pain attitudes than highly acculturated subjects (bottom).
Figure 6. Representative facial expressions during the cold pressor task for the four subcultures
(top to bottom: African American, Hispanic, Asian American and European American).
Figure 7. Males frowned more frequently whereas females smiled more frequently when in pain,
with larger sex differences for Hispanic subjects.
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