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Apology Isn’t Good Enough: An Apology Suppresses an Approach Motivation but Not the Physiological and Psychological Anger Kenta Kubo1, Kazuo Okanoya1,2,3, Nobuyuki Kawai1,4*
1 Okanoya Emotional Information Project, Exploratory Research fpr Advanced Technology (ERATO), Japan Science and Technology Agency, Nagoya, Japan, 2 RIKEN
Laboratory, Brain Science Institute, Wako, Japan, 3 Department of Cognitive and Behavioral Sciences, The University of Tokyo, Meguro, Japan, 4 Department of Cognitive
Science, Nagoya University, Nagoya, Japan
Abstract
Although studies have emphasized the multiple components of anger, little is known about the physiological and psychological mechanisms of the approach motivational component and the negative emotional component of anger. In the present study, participants wrote brief opinions about social problems (e.g., tuition hikes) and received a handwritten, insulting comment about their composition from the experimenter. Half of the participants (apology group) received a simple apologetic sentence at the end of the insulting comment. Half of the participants (no apology group) did not receive one. The physiological responses of the participants were recorded prior to, and after they read the comments. Increases in heart rate and asymmetric frontal brain activity were suppressed only in the apology group. Both groups showed an increase in skin conductance response. Our psychological scales showed that the apology suppressed self reported state anger from an approach-motivational standpoint but not from a negative emotional standpoint. The results suggest that anger is not a unitary process but has multiple components. The apology did provide a different physiological profile but did not dampen down the subjective experience of anger. Thus, providing an apology may not always be effective for alleviating the experience of anger to an insult.
Citation: Kubo K, Okanoya K, Kawai N (2012) Apology Isn’t Good Enough: An Apology Suppresses an Approach Motivation but Not the Physiological and Psychological Anger. PLoS ONE 7(3): e33006. doi:10.1371/journal.pone.0033006
Editor: Tom Denson, The University of South Wales, Australia
Received August 12, 2011; Accepted February 8, 2012; Published March 22, 2012
Copyright: � 2012 Kubo et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Funding: This work is supported by funding from the Japan Science and Technology Agency, Exploratory Research for Advanced Technology, Okanoya Emotional Information Project. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Competing Interests: The authors have declared that no competing interests exist.
* E-mail: [email protected]
Introduction
Given the consequences of actions resulting from extreme
anger, the ability to successfully reduce the anger response is
essential for social harmony. One common way to suppress anger
is to apologize to the angered person. Although we often see
people apologizing as a way to soothe anger, little is known about
the efficacy of the apology and underlying mechanisms (e.g.
physiological and neural) involved when an angered person has
received an apology. A recent study showed that after experienc-
ing a transgression in a trust game, people who received an actual
apology were less satisfied than people who only imagined
receiving one [1]. One interpretation for this result is that an
apology may not be as effective in suppressing anger because the
apology does not necessarily signal repentance. Perhaps, at best, it
can indicate that the person giving the apology has positive
qualities.
Previous research suggests that an apology is effective in
reducing at least one component of anger. In one study, an
experimental assistant prevented a participant from performing a
task [2]. After the task, the experimenter told the participants that
they performed poorly. Although participants experienced anger,
those who received an apology from the assistant reported a
significantly lower aggression score than those who did not receive
one [2,3]. An apology also affects the anger-elicited physiological
reactions in the autonomic nervous system (ANS). When people
experience anger, arousal is observed in the form of muscle
tension, accelerated heartbeat, changes in breathing, and flushing
in the face. These experiences are characterized by changes in
ANS activity. According Ekman et al. (1983), anger produces a
higher heart rate (HR), higher skin temperature, and a larger skin
conductance response. These ANS patterns can be distinguished
from those of other basic emotions [4]. In one study, when
angered participants received a sincere apology from an adversary,
anger-related high blood pressure recovered more quickly than for
participants who did not receive an apology [5]. These results
indicate that an apology may be effective in suppressing
physiological expressions of anger. However, it is still unclear
whether such a change in physiology appropriately reflects the
subjective experience of anger.
Anger is said to include multiple components [6,7]. It is thought
to include not just a negative emotional component, but also an
approach motivational component [8,9,10,11,12,13]. Recent
studies have emphasized the approach motivational component
of anger. This component of anger has been well characterized by
changes in the central nervous system (e.g., asymmetric frontal
brain activity from electroencephalogram (EEG) recordings
[8,14]). One study showed that when people became angry after
PLoS ONE | www.plosone.org 1 March 2012 | Volume 7 | Issue 3 | e33006
receiving insulting comments, they exhibited greater alpha
frequency power in the right frontal area than in the left area
[11]. Because alpha power is inversely related to activity, greater
right frontal alpha frequency suggests greater left frontal activation
[12,13,14,15]. Interestingly, reducing the approach motivation of
the participants can eliminate this asymmetric frontal brain
activity. People in a supine body position did not show asymmetric
frontal brain activity even though they read insulting comments
that had been made about them. However, people sitting naturally
on a chair showed asymmetric activity [16]. Another study
reported the elimination of asymmetric brain activity by
preventing the approach motivation of the angered person [12].
Importantly, the lack of asymmetry does not necessarily mean that
people did not feel anger. They still felt anger even when they did
not show asymmetric brain activity [12]. In other words, the
suppression of the approach motivation of anger may not be
sufficient for suppressing the subjective experience of anger
[12,16].
Very little is known about how an apology affects anger. Does
an apology suppress only the negative emotional component, the
motivational component, or both? Critical information is lacking
on how these components relate to the physiological responses in
the central nervous system and the ANS as well as to the subjective
experience of anger. To our knowledge, no study has examined
whether asymmetric frontal brain activity relates to ANS activity
in response to anger [4]. For the current study, we recorded EEG
signals, HR and skin conductance levels (SCL) and subjective
measures of emotion in order to gain a better understanding of the
neural and psychological mechanisms involved in an apology’s
influence on anger. We set up an insult situation to provoke anger
in the participants [11,16]. Half of the participants received a
simple apology sentence after receiving an insulting comment
(apology group). The other half of the participants did not receive
the apology (no apology group). To dissociate the approach
motivational component and the negative emotional component
of psychological anger, we employed two subjective emotion
indices: PANAS and STAXI. The Positive and Negative Affect
Schedule (PANAS) [17] measures subjective emotions in two
independent dimensions (positive and negative emotion terms).
The PANAS has been widely used as a measure of the subjective
experience of anger and cortical asymmetry activity in past studies
[18,19,20]. We used the Japanese version of the PANAS [21],
which is based on the 20-item English version containing positive
and negative affect subscales. Due to the approach motivational
component of anger, the PANAS can sometimes detect the
positive affective component of anger [19,22]. Several studies have
created tailored questionnaires in order to assess the approach
motivational component of anger [11,18,23,24,25,26]. However,
we utilized a standardized scale used both in western countries and
in Japan to avoid translation problems when assessing the
motivational component of anger. We employed the State-Anger
scale in the State-Trait Anger Expression Inventory (STAXI)
[27,28] to measure the approach motivational component of anger
(the intensity of anger as an emotional state at a particular time;
e.g., I feel like hitting someone), and it has previously been used to
assess the approach motivational component of anger [29].
We predicted two possible outcomes. One possibility was that
an apology would eliminate the approach motivational component
of anger thus eliminating asymmetric frontal brain activity;
however, the apology would not extinguish the subjective
experience of anger [12,16]. The other possibility was that the
apology would eliminate not only the approach motivational
component of anger, but also the subjective experience of anger.
In either case, we predicted that the asymmetry of frontal brain
activity would be altered so long as the apology was effective. We
were particularly interested in determining whether ANS activity
would be affected by receiving an apology following an insult.
Results
We conducted a four-way analysis of variance (ANOVA): 2
(Group: no-apology vs. apology)62 (Gender: male vs. female)62 (Period: baseline vs. insult)62 (Asymmetry: left vs. right) for the EEG data. We also conducted a three-way ANOVA without
asymmetry for the HR and SCL measures. However, neither the
main effect of gender (Fs,1.69, ps..18, g 2 s,.04) nor any of the
interactions with gender (Fs,.14, ps..71, g 2 s,.03) were signifi-
cant among the three measures. Thus, the subsequent analyses
excluded gender as a factor.
EEG Results As in previous studies [12,16,18], the alpha power values at
each brain site (F7 and F8) were submitted to a natural log
transformation to normalize the distributions. Next, asymmetry
indices were calculated by subtracting from log (F8) to log (F7).
The asymmetry scores are displayed in Figure 1.
Greater asymmetry in frontal brain activity was observed when
participants (no-apology group) read the insulting sentences
without the apology comment (Figure 1) but not when the
participants (apology group) read the same sentences with the
simple apology. A two-way ANOVA (Group6Period) revealed a significant interaction between Group and Period, F(1, 46) = 6.32,
p = .015, g 2
= .12; however, the main effects of Group, F(1,
46) = 1.32, p = .256, g 2
= .028, and Period, F(1, 46) = .49, p = .488,
g 2
= .011, were not significant. To deconstruct the significant
interaction, post-hoc tests (t-test) were conducted in each group.
The asymmetry index significantly increased in the no-apology
group following the insulting comments, t(23) = 2.84, p = .009,
r = .51, 95% confidential interval (CI) = 2.03, 2.007. However,
there was no significant difference between the two periods in the
apology group, t(23) = 1.10, p = .282, r = .22, 95% CI = 2.009, .03.
These results suggest that the simple apology reduced the
approach motivation of anger.
Figure 1. The asymmetry indexes for each group were displayed in the baseline and the insult periods. The open circles illustrate the no-apology group (N = 24). The closed circles illustrate the apology group (N = 24). Each vertical line illustrates the standard error for each condition. doi:10.1371/journal.pone.0033006.g001
Apology Isn’t Good Enough
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It is possible that the apology ‘‘prevented’’ the increase in
approach motivation or participants may have just displayed a
quick recovery after approach motivation increased [2,3,5].
Detailed analyses suggest the former. The alpha power showed
significant asymmetry for the no-apology group, t(23) = 5.03,
p = .0001, 95% CI = 2.012, .05, but not in the apology group
during the earliest 30 seconds of the recording period, t(23) = 0.19,
p = 2.62, 95% CI = 2.18, .061. The HR response of the no-
apology group also increased significantly in the earliest 30 sec-
onds, t(23) = 3.97, p = .008, 95% CI = 28.0, 2.15, whereas HR
response of the apology group did not increase during the same
period, t(23) = .17, p = .008, 95% CI = 2.10, .15.
ANS Results Figure 2 shows the results of the ANS measures in the two groups.
The HR results showed a similar pattern to that of the EEGs
(Figure 2A). When participants read the insulting comments, the
HR response of the apology group increased sharply, whereas it
increased mildly in the apology group. A 2 (Group: apology vs. no-
apology)62 (Period: baseline vs. insult) ANOVA yielded a main effect of Period, F(1, 46) = 7.73, p = .008, g
2 = .144; however, the
main effect of Group, F(1, 46) = .28, p = .636, g 2
= .005, and the
interaction, F(1, 46) = 1.89, p = .176, g 2
= .039, were not significant.
Given the significant interaction in the EEG measure and our
special interest in the ANS measures following the insult, we
performed planned comparisons in each group. The HR response
in the no-apology group increased significantly following the insult,
t(23) = 3.28, p = .003, r = 0.56, 95% CI = 26.75, 21.53; however,
the HR response of the apology group did not increase, t(23) = .91,
p = .373, r = 0.19, 95% CI = 24.59, 21.79, suggesting a differential
effect of a simple apology on HR reactivity.
Results of the SCL were different from the EEG and HR results
(Figure 2B). Both groups showed increased SCL response following
the insult. A 2 (Group: apology vs. no-apology)62 (Period: baseline vs. insult) ANOVA revealed a main effect of Period, F(1,
46) = 17.91, p = .0001, g 2
= .280; however, the main effect of
Group, F(1, 46) = .0002, p = .989, g 2
= .000004, and the interaction
were not significant, F(1, 46) = .012, p = .913, g 2
= .0003. A planned
comparison in each group showed a significant increase in the SCL
in both groups (no-apology: t(23) = 3.01, p = .006, r = 0.53, 95%
CI = 2.89, 2.16; apology: t(23) = 2.97, p = .007, r = 0.53, 95%
CI = 2.85, 2.15), suggesting that the SCL measure was sensitive to
the insult but was insensitive to the simple apology.
Results of psychological anger The results of psychological anger are summarized in
Table 1. The no-apology group showed higher STAXI scores
than the apology group, while both groups reported increased
STAXI scores in the insult period. A 2 (Group: apology vs. no-
apology)62 (Period: baseline vs. insult) ANOVA confirmed these observations. The main effects of Group, F(1, 46) = 6.40, p = .015,
g 2
= .122, and Period, F(1, 46) = 23.61, p = .00001, g 2
= .339, were
significant. Importantly, the interaction was also significant,
F(1,46) = 15.39, p = .00001, g 2
= .251. Post-hoc analyses revealed
an increase in anger in the no-apology group, t(23) = 4.59,
p = .0001, r = 0.69, 95% CI = 2.73, 2.28, but no increase in
anger in the apology group, t(23) = 1.62, p = .120, r = 0.32, 95%
CI = 2.12, .02. These results suggest that the apology suppressed a
subjective anger state as measured by the STAXI.
Results from the negative affect subscale of the PANAS were
not different between the two groups. A two-way ANOVA
revealed a main effect of Period, F(1, 46) = 39.24, p,.000001,
g 2
= .631. However, the main effect of Group, F(1, 46) = .48,
p = .490, g 2
= .010, and the interaction, F(1, 46) = .003, p = .957,
g 2
= .00006, were not significant. A two-way ANOVA was also
performed on the positive affect subscale of the PANAS. The main
effect of Period was significant, F(1, 46) = 4.60, p = .037, g 2
= .091;
but, again, the main effect of Group, F(1, 46) = .009, p = .924,
g 2
= .0002, and the interaction, F(1, 46) = .323, p = . 572,
g 2
= .007, were not significant.
The STAXI results seem to correspond with the EEG and HR
results. Conversely the results of the negative affect subscale of the
PANAS seemed to correspond with those of the SCL. Therefore, we
examined correlations between the negative affect subscale scores
from the PANAS and the physiological measures in the two groups.
There was no significant correlation between the negative affect
subscale and the SCL measure (no-apology: r = .004, N = 24, p = .986;
apology: r = 2.003, N = 24, p = .989). There was also no significant
correlation between the STAXI and the HR measure (no-apology:
r = 2.182, N = 24, p = .394; apology: r = 2.233, N = 24, p = .273).
Discussion
In the present study, an apology eliminated the asymmetry in
frontal brain activity and but influenced an increase in HR
reactivity; however, the apology did not affect changes in SCL
reactivity in response to an anger provocation. Previous studies
Figure 2. The results of HR (A) and SCL (B) for each group were displayed in the baseline and the insult periods. Each vertical line illustrates the standard error for each condition. doi:10.1371/journal.pone.0033006.g002
Apology Isn’t Good Enough
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have shown that asymmetrical frontal brain activity reflects the
approach motivational component of anger [8,9,11,12,13,14].
The simple apology used in this study also successfully suppressed
the approach motivational component of anger. However, the
restricted efficacy of the apology was evident in the psychological
scales. Studies have shown that the prevention of the approach
motivation reduces the asymmetry of frontal brain activity but it
does not necessarily reduce the subjective experience of anger
[12,16]. Consistent with these findings, an anger state relevant to
the approach motivation (via the STAXI) was reduced by the
apology, whereas subjective scores of negative emotion (via the
PANAS) were not altered either with or without the apology.
These results correspond with the participants’ introspective
reports: no one was soothed by the apology in this study.
Therefore, our results suggest that, the simple apology had little
effect on calming down the experience of anger.
The most interesting finding was that the HR and the SCL
reactivity showed different susceptibility to the apology. Several
studies examining anger have demonstrated that both HR and the
SCL reactivity increase when people get angry [4,30]. This was
the case in the present study for the no apology group. However,
the HR and the SCL responses are assumed to reflect different
components of anger. The HR reactivity as well as the
asymmetrical frontal brain activity is assumed to reflect the
approach motivational component, whereas SCL responses reflect
the negative emotional component of anger (see Figure 2 and
Table 1). This view is consistent with the distinction between anger
and fear. An increase in SCL response is observed when people
experience both anger and fear [4,30]. Conversely, HR reactivity
typically does not increase when experiencing fear [4,30]. Both
fear and anger produce the negative emotional component, which
corresponds to an increase in SCL reactivity. The major
distinction between anger and fear is the approach motivation
component. In the case of anger, HR reactivity increases, while
this is not the case for fear. The present study suggests that anger is
not a unitary process as a basic emotion but has multiple
components that can be measured through different physiological
activities. Further examination will be needed to clarify how these
ANS measures change in response to an insult and the following
apology. This is important given that HR activity has a complex
relationship with emotion, motivation, and attention. Thus,
increased HR reactivity might not necessarily reflect approach
motivation, alone.
Why are apologies ubiquitous all over the world despite having
such a limited effect on anger? When aggression [11,13,31] or
approach motivation [12,16,32] is suppressed, frontal brain
asymmetry has been eliminated in response to anger provocation.
An apology may be efficacious in suppressing the asymmetry of
brain activity (e.g., the approach motivation of the angry person),
which may help people avoid being the victim of anger. The
apology may allow the person giving the apology to avoid a violent
outburst from the angry person; however, this may not eliminate
the experience of negative emotion for the angered person.
In summary, the present study clearly showed that anger is not a
unitary process but has multiple components that appear as
different physiological reactions to an apology. An apology may
eliminate the approach motivational component of anger without
affecting the subjective experience of anger as measured by SCL.
Materials and Methods
Participants Forty-eight students (female = 24, mean age = 20.5) from a local
university participated in the experiment. All participants were
right-handed, as assessed by the Edinburgh Handedness Inventory
[33], and had normal or corrected-to-normal vision according to a
self-report. All participants were naive to the purposes of the
experiment and gave their written informed consent. The Ethics
Committee of the Japan Science and Technology Agency
approved the experimental protocol.
Procedure The participants came to the laboratory under the assumption
that there was another participant in another experimental room.
The experimenter was careful to drop subtle hints during the
course of the experiment to make this cover story believable.
Participants were told this experiment would record EEG and
ANS when they are discussing social problems (e.g., a tuition hike,
smoking in public) by exchanging their brief, hand-written
opinions.
After obtaining consent, EEG and ANS sensors were attached
to the participants. Then, during a 2 min rest period, baseline
EEG and ANS data were recorded. After the baseline recording,
participants completed the PANAS and the STAXI question-
naires. Next, participants were told they had been randomly
assigned to write an essay and that the other participant would
evaluate it. The participants were given 10 min to write the essay.
The essay was then brought to the other fictitious participant for
evaluation, while the participants received a handwritten essay by
the fictitious counterpart and asked to evaluate it. The evaluation
included ratings of the essay on six characteristics using a 9-point
scale (e.g., for intelligence, 1 = unintelligent, 9 = intelligent). In
addition, there was a comment column on the evaluation sheet
where the participants were required to provide a comment about
the counterpart’s essay. The evaluation by the fictitious counter-
part was then returned to the participants. All participants were
given the following ratings: intelligence = 3, interest = 3, friendli-
ness = 2, logic = 3, respectability = 4, and rationality = 3. Each
essay was also provided with this comment: ‘‘I can’t believe an
educated person would think like this. I hope this person learns
something while at university.’’ [11]. A female handwrote all of the
feedback. This insult manipulation has been successfully used in
prior studies [11,16]. However, there were extra comments
provided in the present experiment. For the no apology group,
the second comment said, ‘‘That is all of my comments.’’ For the
apology group, the second comment said, ‘‘I’m sorry for making
such a critical comment on your essay.’’ were added to the end of
the above insulting sentence as the experimental manipulation.
The participants were required to read the feedback ratings and
comments silently for 2 min while EEG and ANS data were
recorded. They next filled out the subjective emotional question-
Table 1. Mean rating scores and standard error of subjective scales (PANAS and STAXI) for the no-apology group and the apology group.
no-apology apology
baseline insult baseline insult
PANAS
Positive 2.8 (0.2) 2.5 (0.2) 2.7 (0.2) 2.5 (0.3)
Negative 1.6 (0.1) 2.9 (0.2)* 1.8 (0.1) 3.1 (0.2)*
STAXI 1.1 (0.04) 1.6 (0.1)* 1.1 (0.03) 1.1 (0.1)
*:baseline,insult (ps,.05). doi:10.1371/journal.pone.0033006.t001
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naires (PANAS and STAXI) for a second time. Participants were
debriefed at the end of the experiment.
Recordings EEG signals were recorded from lateral frontal sites (F7, F8
according to the 10–20 system) using Ag/AgCl electrodes. The
ground electrode was mounted at the midline between the frontal
pole and the frontal site. The reference electrode was placed at the
tip of the nose. Vertical eye electrooculograms (EOGs) were also
recorded to facilitate artifact correction of the EEG. All electrode
impedances were under 5 kV. The sampling rate of the EEG was 500 Hz. EEGs and EOGs were amplified with an MP150 data
acquisition system (BIOPAC Systems, Inc., Goleta, CA), a digital
bandpass filter of (0.5–30 Hz) was applied, and ocular artifacts
were corrected using the method described in a previous study
[34]. Alpha power was calculated by fast Fourier transform using a
Hamming window within the alpha band (8–13 Hz). Because
alpha power is inversely related to cortical activity, higher alpha
power on the right side than the left side indicates greater activity
in the left than the right [15,35].
HR and SCL were recorded by an MP150 system (BIOPAC
Systems, Inc., Goleta, CA). HR was recorded from the left and
right wrists by disposable electrodes. From the 2-min baseline data
and the silent reading of the insult sentence, the beats per minute
(bpm) were extracted using Acknowledge software (BIOPAC
Systems, Inc., Goleta, CA). For the SCL recordings, two sweat-
isotonic electrodes were placed on the palmar sites of the middle
phalanges of the second and third fingers of the left hand [36].
SCL was calculated by averaging the skin conductance response
amplitude in the 2 min baseline period and during the silent
reading of the insult sentence. Both ANS measures were sampled
at 500 Hz.
Subjective affect scales were administered after recording
psychophysiological data during the baseline and insult periods.
We used two measures as a subjective scale to assess anger, the
PANAS and STAXI. The PANAS is an inventory of a
participant’s mood on a 7-point scale (1 = very slightly, 7 = ex-
tremely) to positive/negative items [17]. The present experiment
used the Japanese version of the PANAS [21], which was based on
the original PANAS. The STAXI [27,28] was also used as a
subjective scale for anger in the present experiment. We used 10
items of state-anger in the Japanese STAXI to assess the state
anger of the participants on a 4-point scale (1 = almost never,
4 = almost always). The participants also completed both scales
after they read the comments provided by the insult manipulation.
Author Contributions
Conceived and designed the experiments: KO. Performed the experiments:
KK. Analyzed the data: KK. Wrote the paper: NK. Arrangement of the
study: NK.
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Apology Isn’t Good Enough
PLoS ONE | www.plosone.org 5 March 2012 | Volume 7 | Issue 3 | e33006
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