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Contagious yawning and psychopathy

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Psychopathy is characterized by a general antisocial lifestyle with behaviors including being selfish, manipulative, impulsive, fearless, callous, possibly domineering, and particularly lacking in empathy. Contagious yawning in our species has been strongly linked to empathy. We exposed 135 students, male and female, who completed the Psychopathic Personality Inventory-Revised (PPI-R), to a yawning paradigm intended to induce a reactionary yawn. Further, we exposed males to an emotion-related startle paradigm meant to assess peripheral amygdalar reactivity. We found that scores on the PPI-R subscale Coldheartedness significantly predicted a reduced chance of yawning. Further, we found that emotion-related startle amplitudes were predictive of frequency of contagious yawning. These data suggest that psychopathic traits may be related to the empathic nature of contagious yawning in our species.
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Contagious yawning and psychopathy
Brian K. Rundle , Vanessa R. Vaughn, Matthew S. Stanford
Baylor University, Department of Psychology and Neuroscience, One Bear Place 97334, Waco, TX 76798, United States
abstractarticle info
Article history:
Received 25 March 2015
Received in revised form 18 May 2015
Accepted 19 May 2015
Available online xxxx
Keywords:
Yawn
Startle
Psychopathy
Evolution
Psychopathy is characterized by a general antisocial lifestyle with behaviors including being selsh, manipula-
tive, impulsive, fearless, callous, possibly domineering, and particularly lacking in empathy. Contagious yawning
in our species has been strongly linked to empathy. We exposed 135 students, male and female, who completed
the Psychopathic Personality Inventory-Revised (PPI-R), to a yawning paradigmintended to induce a reactionary
yawn. Further, we exposed males to an emotion-related startle paradigm meant to assess peripheral amygdalar
reactivity. We found that scores on the PPI-R subscale Coldheartedness signicantly predicted a reduced chance
of yawning. Further, we found that emotion-related startle amplitudes were predictive of frequency of conta-
gious yawning. These data suggest that psychopathic traits may be related to the empathic nature of contagious
yawning in our species.
© 2015 Elsevier B.V. All rights reserved.
1. Yawning and psychopathy
Yawning is a stereotyped behavior that, in our evolutionary history,
has clear, deep roots as evidenced by its proliferation in mammals as
well as many other vertebrates (Argiolas and Melis, 1998; Lehmann,
1979). It is clearly characterized by long inspiration followed by a
shorter expiration (Argiolas and Melis, 1998). While literature con-
cerning the pharmacology and functional anatomy of yawning is not
lacking (Argiolas and Melis, 1998; Guggisberg, Mathis, Schnider, and
Hess, 2010; Nahab, Hattori, Saad, and Hallett, 2009), the primary facet
of yawning of interest is the phenomena of contagious yawns, speci-
cally within the context of psychopathology.
Contagious yawns, which are spurred by yawn, thinking, hearing,
reading, or observing another conspecic(orotherspecies),have
been linked to empathy (Lehmann, 1979; Platek, Critton, Myers,
and Gallup, 2003; Platek, Mohamed, and Gallup, 2005). They are
even documented in other familiar animals such as Pan Troglodytes
and Canis Familiaris and have been linked to empathy (Campbell
and de Waal, 2011; Romero, Konno, and Hasegawa, 2013). The anat-
omy and pharmacology of yawning and its contagious nature are be-
ginning to be investigated, with oxytocin playing a large role as well
as the posterior cingulate cortex (PCC), precuneus, bilateral thala-
mus, and parahippocampal gyrus (PHG) (Platek et al., 2005; Sanna,
Argiolas, and Melis, 2012). Interestingly, Schürmann et al. (2005)
found that the mirror-neuron system is not directly activated in
contagious yawning, suggesting that the action is automatic and
not imitated. Norscia and Palagi (2011) found that people show a
large susceptibility to contagious yawns when elicited by a related
individual in terms of occurrence and frequency of yawns. For
strangers, they found that people show a marked latency period of
contagious yawns, strongly suggesting a component of familiarity
involved with the contagion.
Variations in susceptibility to contagious yawning are already
known to occur in certain populations. Age is known to affect the likeli-
hood of contagious yawning; as age increases, contagious yawning de-
creases (Bartholomew and Cirulli, 2014). Further, children on the
autism spectrum are less likely to demonstrate contagious yawning
(Giganti and EspositoZiello, 2009; Senju et al., 2007), which is speculat-
ed to have a strong relationship to the empathetic decits seen in this
population.
1.1. Psychopathy
Empirical support for yawning having its evolutionary roots in
empathic behavior is growing (Campbell and de Waal, 2011).
Psychopathic traits, then, become a curious angle in which to view
contagious yawning in our species. Psychopathy is characterized
by a general antisocial lifestyle including being selsh, manipula-
tive, impulsive, fearless, callous, domineering, and particularly lack-
ing in empathy (Hare, 2003; Weber, Habel, Amunts, and Schneider,
2008). The disorder is typically assessed via the Psychopathic Check
List-Revised (PCL-R) developed by Hare (2003) or the Psychopathic
Personality Inventory (PPI-R) developed by Lilienfeld and Widows
(2005). Psychopathy and its close relative Antisocial Personality Disorder
are found overwhelmingly in males (Cale and Lilienfeld, 2002). Addi-
tionally, psychopathy carries specic brain abnormalities including
structural and functional impairments of the orbitofrontalventromedial
prefrontal cortex as well as the amygdala (Gao, Glenn, Schug, Yang, and
Raine, 2009; Weber et al., 2008).
Personality and Individual Differences 86 (2015) 3337
Corresponding author.
E-mail address: Brian_rundle@baylor.edu (B.K. Rundle).
http://dx.doi.org/10.1016/j.paid.2015.05.025
0191-8869/© 2015 Elsevier B.V. All rights reserved.
Contents lists available at ScienceDirect
Personality and Individual Differences
journal homepage: www.elsevier.com/locate/paid
The PPI-R operationalizes two discrete components within psychop-
athy: a primary (affective) and secondary (behavioral) facet (Hare,
2003; Lilienfeld and Widows, 2005), where the primary facet encom-
passes features including cruelty, lack of affect and empathy, while the
secondary facet encompasses features such as impulsivity and aggres-
sion. Psychopaths demons trate an overall small bu t marked decrea se
in the ability to recognize emotion in others (Kosson, Suchy, Mayer,
and Libby, 2002; Wilson, Juodis, and Porter, 2011), which is also
associated with decreased amygdalar function, particularly with
fearful faces (Jones, Laurens, Herba, Barker, and Viding, 2009).
Kosson et al. (2002) showed a slight overall decreased ability to rec-
ognize emotion, but a large decit in recognizing disgust in others
when the task involved non-verbal responses. It has also been
shown that psychopaths fail to exhibit a conditioned response to aver-
sive Pavlovian conditioning (Flor, Birbaumer, Hermann, Silvio, and
Patrick, 2002), which suggests deciencies in amygdala-dependent
memory.
What sets psychopathy apart from its close relatives Conduct Disor-
der and Antisocial Personality Disorder is its distinct emotional compo-
nent. That is, psychopathy involves a prevalent emotional prole
consisting of a considerable reduction in or lack of empathy (Frick,
O'Brien, Wooton, and McBurnett, 1994; Hare, 2003). Psychopathy has
also been found to be inversely related to the ability to perceive emotion
(in both male and females) and managing emotion (only in men)
(Lishner, Swim, Hong, and Vitacco, 2011).
1.2. Hypothesis
Given the nature of psychopathy and yawning discussed herein, the
current study aims to examine the relationship between contagious
yawning and psychopathic traits. This will be examined both by a yawn-
ing paradigm designed by the current researchers (modeled after Platek
et al., 2005) as well as an emotion-related startle paradigm (ERS) previ-
ously used in Anderson, Stanford, Wan, and Young (2011).Affectivepo-
tentiation of the acoustic startle reex (by Electromyograph [EMG] and
Galvanic skin response [GSR]) is one of the most prominent psycho-
physiological measures of amygdalar responsiveness (Davis, 1989;
Lang, Bradley, and Cuthbert, 1990; LeDoux, Iwata, Cicchetti, and Reis,
1988). Psychopaths reliably demonstrate an impairment of potentiation
of the startle reex (Patrick, Bradley, and Lang, 1993), while healthy
controls reliably potentiate with negative affective valence and attenu-
ate the fearresponse with positive affective valences (Lang et al., 1990).
What's more, Patrick et al. (1993);Patrick (1994) connected the lack
of potentiated startle in psychopathy to the emotional facet of the
PCL-R (Hare, 2003) while the behavioral facet was found to be unre-
lated. Further, given the growing evidence that contagious yawning
and empathy are evolutionarily related, a connection between
psychopathy and yawning maintains sufcient precedence. To
our knowledge, such an examination has not been done in high
psychopathic trait individuals, nor have contagious yawning been
addressed using ERS. In our case, we expect to nd a connection
between psychopathic traits and a decreased susceptibility to conta-
giously yawn.
2. Methods
In these experiments, a total of 135 college male and female
participants were selected based on their completion of the PPI-R
(Lilienfeld and Widows, 2005). Psychopathic traits were operation-
alized as a spectrum and no arbitrary cut-off was used for high and
lowtraits unless noted. The PPI-R has three primary factors: Fearless
Dominance (FD)/Self-Centered Impulsivity (SCI; behavioral and in-
terpersonal aspects), and Coldheartedness (CD; social emotional
aspect).
2.1. Experiment one: yawn
2.1.1. Participants
For the yawning paradigm, one hundred and thirty ve univer-
sity students, males (n = 57) and females (n = 78), were used.
All participants completed the same yawning paradigm intended
to induce a reactive yawn. Participants were excluded from the
analyses if they resisted yawning or did not pay attention to the
presentation.
2.1.2. Yawn paradigm
Videos of individual males and females unknown to any partici-
pants were selected to provide 7-10 second videos of a yawn, a
laugh, or a neutral face. This paradigm follows the methods listed
in Platek et al. (2005), a method shown to induce yawns. Partici-
pants viewed a series of video blocks. Each block consisted of three
videos (yawning, neutral-face, and smile) in random order. To be
clear, each video block did not contain the videos from one individ-
ual, but rather a pseudo-random and exhaustive selection of yawns,
laughs, or neutrals from a pool of videos recorded from strangers.
Each individual video was 710 s long and, thus, each block was
2433 s long (with a one second interval between each video in
the video block). Ten seconds of a blank black screen separated
each block and participants viewed 20 blocks.
2.1.3. Procedure
Participants were instructed to sit in a padded chair in a dimly lit,
radiofrequency anechoic chamber (Raymond EMC Enclosures Ltd.
Ottawa). Participants sat in front of a computer monitor and wore
noise canceling headphones. They were asked to relax for one minute's
time. They were told that they would be watching a movie of different
people's expressions that they need to remain comfortably seated, and
to keep their attention on the screen. Further, if they felt the need to ad-
just themselves, laugh, cough, yawn, or blink, that they were allowed to
do so as long as their attention remained on the screen and that they
would return to a still, comfortable position.
Facial EMG was recorded from the orbicularis oculi muscle of the
participant's right eye. A pair of AgAgCl electrodes (Biopac Systems
Inc., Goleta, CA, USA) was placed one centimeter below the eyelid,
with one directly below the pupil and the other one centimeter to the
right of the rst. A third electrode was placed directly in the middle of
the forehead to serve as a ground. Prior to placing the electrodes, skin
was prepared with an isopropyl alcohol rub and a mildly abrasive gel
(NuPrep) to improve surface conductance. Signa gel brand saline gel
was used as a conducting medium and impedances were kept below
5kΩ. Hardware used to collect EMG signals wasBioPac MP150 data ac-
quisition hardware using a sampling rate of 2000 Hz and a 10500 Hz
bandpass lter. EMG data were rectied and integrated witha time con-
stant of 10 ms.
GSR was also obtained. Electrodermal activity was recorded by se-
curing AgAgCl to the index and ring nger of the participants. Skin
was prepped by removing surface oils with isopropyl alcohol followed
by the application of isotonic NaCl electrode paste. Hardware used to
collect GSR data was BioPac MP150 data acquisition hardware using a
sampling rate of 2000 Hz and a 0.51 Hz bandpass lter. For both
EMG and GSR, data was recorded with AcqKnowledge 4.1 Software
(BioPac Systems Inc.).
Unlike Platek et al. (2005), we were simply interested in in-
ducingyawns.Asavalidationmeasure,EMG,GSR,anddirectvideo
observation of the participant were utilized. That is, a clear physio-
logical characterization of a yawn was necessary for the behavior
to be considered a full yawn. This was in order to distinguish related
behaviors such as sighs and heavy inspirations as well as to validate
video observations. Electrophysiologically, we dened a yawn as
sustained EMG impedance paired with a delayed GSR (see Fig. A.1
34 B.K. Rundle et al. / Personality and Individual Differences 86 (2015) 3337
for an example). All full, validated yawns during the time of the
yawning video were counted.
2.2. Experiment two: startle
2.2.1. Participants
Males from the rst experiment (n = 57) also participated in an
emotional related startle paradigm. Participants were excluded
from the analysis if they were unable to perform any part of the
yawning or startle paradigm sufciently or if they had already
participated in an emotion-related startle paradigm before. Only
males were used in this experiment due to its pilot nature and
the more complex variations in startle potentiation in females
(see Anderson et al., 2011).
2.2.2. Eyeblink startle
An eyeblink startle paradigm established by Anderson et al. (2011)
was used to measure emotion-modulated startle. Affective pictures
from the International Affective Picture System (IAPS; Lang, Ohman,
and Vaitl, 1988) were utilized. The images have standardized ratings
of affective valence and arousal level (Lang and Greenwald, 1988).
An equal number of positive, negative, and neutral pictures were used
(45 total). The particular set of images used in the current paradigm
were selected from a pool previously used in a study by Larson,
Ruffalo, Nietert, and Davidson (2005), which had veried testretest re-
liability in measuring emotion-modulated startle. Anderson et al.
(2011) describes picture selection and exclusion criteria for theIAPS im-
ages used in this study.
Participants were instructed to sit in a padded chair in a dimly lit,
radiofrequency anechoic chamber (Raymond EMC Enclosures Ltd.
Ottawa), which is designed to minimize unnecessary electromagnetic
waves that would potentially interfere with equipment recordings. Par-
ticipants put on noise-canceling headphones, through which the startle
burst was delivered. They sat in front of a computer monitor and were
instructed to relax for one minute. Participants then were instructed
to keep their full attention on the screen during the entire presenta-
tion and were informed that they were going to hear a burst of
white-noise through their earphones, which is to be ignored. Pic-
tures were presented pseudo-randomly in a single block of 60 im-
ages. The order of the pictures was such that no two pictures were
presented serially.
Pictures were on screen for 6 s and followed by a 2 second interstim-
ulus interval which consisted of a white plus sign (+) in the middle of a
black screen for the participantto focus. Thirtyof the pictures contained
a white noise burst, which lasted 50 ms at 100 dB. Startle probes were
assigned randomly to images with an equal number of probes
assigned to each valence category. There were fteen images per va-
lence category with ten paired with the startle probe, which was de-
livered either 3 s or 5 s after the onset of the image. Software used to
present the startle paradigm was Superlab 4.0 (Cedrus Corporation,
San Pedro, CA, USA).
EMG was used to measure the magnitude of the startle response
with the same preparation as mentioned in the yawning paradigm.
Blink magnitudes were dened as smoothed EMG signal, recorded as
baseline to peak differences for each startle probe. In order to establish
a baseline, the mean orbicularis oculi EMG reading during the 25 ms
prior onset of the noise was used; amplitude peaks of interest were de-
ned as the maximum amplitude between 40 ms and 120 ms after the
onset of the noise.
2.2.3. Statistical analyses
For the yawing paradigm, logistic regression was performed on
the overall scale and subscales of the PCL-R on a dichotomous out-
come, namely yawnor no yawn. Further, startle amplitudes
were linearly regressed on frequency of yawning in order to assess
the relationship between emotion-related startle potentiation and
yawning susceptibility. Yawning frequency was recorded for demo-
graphic purposes.
It is important to note that prior to analysis, raw peaks were
standardized within subjects due to the high variability of blink am-
plitude variation. Further, a regression analysis was performed with
the difference score (DS), dened as the mean peak amplitude for
neutral stimuli less the mean peak amplitude for negative stimuli
(see Anderson et al., 2011). Lower numerical values of DS would
suggest more potentiated reactions to negative stimuli. Higher nu-
merical values would suggest less potentiation to negative stimuli,
as the mean peak amplitude for negative stimuli would be a smaller
value.
3. Results
3.1. Experiment one
The mean age for the participants in this study was 18.89, SD = 1.13.
In terms of observed yawns (133) within the paradigm, the modal num-
ber of yawns was zero followed by 1, 2, and 3 yawns respectively
(Fig. A.2).All yawns included in the analyses met the physiologically de-
ned parameters. Individuals with highly atypical Inconsistent
Responding scores (an internal validation measure to the PPI-R) were
removed from the analyses. As well, the invalid participants (listed in
experiment 2) were also excluded. Females were more likely than
males to yawn during the paradigm, but a statistically signicant gender
effect was not shown, β=0.432,p= .249. Next, a test looking at sus-
ceptibility to yawn by high and low traits on the overall score of the
PPI-R showed β=0.008, p= 0.154. Sub-factor tests showed
β=0.15, p= 0.129 for Fearless Dominance; Self-Centered Impul-
sivity showed β=0.001, p= 0.923; and β=0.062, p= 0.020
for Coldheartedness. Estimates and Standard Errors are summated
in Table A.1.
Diagnostic clinical signicance for psychopathy is the 65th percen-
tile and above. Though arbitrary, we evaluated the difference be-
tween clinically signicant scores and non-signicant scores. The
average number of yawns for a low-trait individual on the CD scale
was M= 3.36, SD = 3.72, while the average number of yawns for in-
dividuals high on CD traits was M= 1.96, SD = 3.11. An independent
samples t-test was performed between high and low trait partici-
pants on the Coldheartedness sub-factor and number of yawns
showing, t(121) = 2.184, p= .031; CI(95%) = .132 bμb2.680,
d= 0.40.
3.2. Experiment two
EMG data during the startle paradigm were analyzed. When
the DS between the mean peak of neutral pictures and negative
pictures was examined using a regression analysis (see experiment
2), the values were notably predictive of yawning frequency
(β=1.110, pb.001). Thus, the lower the startle response, the
less likely a participant was to yawn in response to the yawning
presentation.
4. Discussion
4.1. Experiment one
While psychopathy is not simply the lack of empathy, endorsement
of the CD subscale is strongly indicative of damped empathic affect. The
theory that contagious yawning in our species is largely mediated by
empathy is supported by the signicant difference between genders
on probability of yawning (63.5% of women yawned compared to
53.1% of males), as females tend to score higher on measures of em-
pathy than males (Rueckert, Branch, and Doan, 2011). Further, as previ-
ously discussed, psychopathy is almost exclusively diagnosed in males.
35B.K. Rundle et al. / Personality and Individual Differences 86 (2015) 3337
It is expected that a higher percentage of females would yawn dur-
ing the paradigm; however, since there was no statistical difference
between genders, a gender effect on likelihood to yawn can be easily
controlled. This difference merely shows that the paradigm itself
maintains a level of validity consistent with the existing literature
that would be expected. It is true that this is an indirect expectation
by means of empathy; to our knowledge, no conclusive evidence between
gender and contagious yawning has been established (Baenninger,
Binkley, and Baenninger, 1996).
When evaluating the all subscales, only CD yielded signicant re-
sults. This is not surprising considering that the grouping variables
SCI or FD do not wholly capture the emotional component (or lack
thereof) of psychopathy and tend to focus on behavioral and
interpersonal factors. A difference between groups suggests that
increased CD is associated with decreased susceptibility to a conta-
gious yawn. Further, when considering the overall PPI-R score,
which includes all subscales,
1
a strong trend towards signicance is
seen, which is likely mediated by Coldheartedness. When compared
to other sub-factors, FD and SCI, Coldheartedness clearly maintains
the largest affective component on the PPI-R (Lilienfeld and
Widows, 2005).
In line with theory and previously shown between genders, in-
creased empathy is associated with increased susceptibility to conta-
gious yawning (Platek et al., 2003). Using psychopathy as a predictor
of susceptibility of contagious yawning may, then, be a viable avenue
of research simply by virtue of the interpersonal and emotional abnor-
malities associated with psychopathy. The results of this experiment
lend support to the theory that empathy and contagious yawning
are related in our species and may work together to accomplish
social ends.
4.2. Experiment two
Though only males were exposed to the startle paradigm as part of a
separate study, yawning data were collected on all participants. A re-
gression analysis showed that the difference between the negative
and neutral mean potentiation was predictive of yawning frequency.
Experiment 2 provides physiological data and a predictive parametric
measure for future study. In this case, the lower the yawning suscepti-
bility, the lower the difference between neutral and negative startle re-
sponse (resulting in an overall higher numerical value). The negative
correlation between the neutral-negative difference and yawning fre-
quency shows that the higher the frequency of yawns, the greater the
difference between the neutral-negative difference (resulting in a
more negative numerical value). Thus, the greater the measured psy-
chopathic traits, the lower the startle potentiation and, therefore, the
lower difference value between neutral and negative. On the other
hand, individuals with lower levels of psychopathic traits showed
greater startle potentiation, which produces a greater difference
value.
The relationship between startle potentiation and emotional dysreg-
ulation is well studied. Aside from the psychopathy-related research
currently presented, startle potentiation is seen in emotional disorders
involvingincreased (and dysregulated) emotional disposition including
anxiety and depression (see Ballard et al., 2014). The available research
gives sufcient pretense to the data collected in these experiments. Our
data suggest that one's level of psychopathic traits and startle reactivity
are related to one's susceptibility to contagious yawning. That is to say,
a well-established physiological measure of psychopathic traits is
also highly associated with the susceptibility to contagious yawning.
The less emotion-related startle reactivity observed, the lower the
susceptibility to contagiously yawn. Both independent variables have
a strong relationship to empathic behavior and emotional regulation,
and taken together, provide insight into thecomplex nature of yawning
and social interaction. While no conclusion can be drawn at this time,
these data are steps forward in elucidating the function of contagious
yawning in our species. Further, this invites inquiry into amygdalar re-
activity as measured by ERS and the PCC, precuneus, thalamus, and
PHG, involved in empathy and self-referent processing (Platek et al.,
2005). Platek et al. suggests these areas may be related to the general
sensory aspects of face-processing.
5. Conclusion
To our knowledge, no experiments showing the relationship be-
tween startle potentiation, psychopathy, and yawning have been
published. It is, however, established the relationship between psy-
chopathy and startle as well as the relationship between yawning
and empathy (Norscia and Palagi, 2011). Though pilot in nature,
our data suggests that startle potentiation to negative stimuli may
predict one's susceptibility to contagious yawning. In line with the
theories presented on yawning and startle, it is reasonable to expect
that low startle potentiation is related to yawning susceptibility, as
affect is highly considered in both realms of research.
There is also an evolutionary justication for the results found here-
in. While psychopathic traits are not the direct inverse of empathetic
traits, both are constructs that seem to capture polarized behaviors.
Coldheartedness refers to a dearth of social emotion (Lilienfeld and
Widows, 2005). That is, it is an inconsideration of the emotional state
of others. Our results, then, t well into the evolutionary model that
contagious yawning in our species is a function of empathy, as we
have shown that those who are characteristically lacking in empathy
are less susceptible to a contagious yawn when prompted in a paradigm
known to induce contagious yawning in normal individuals (Platek
et al., 2003).
The results of these two experiments are clear indicators that psy-
chopathy is a robust, multifaceted disposition, where a strict interpreta-
tion of an overall PPI-R score is not necessarily a predictive one. Rather,
attention to subscales and, of course, clinical evaluations are clearly
more appropriate for predictability. While gender effects between
yawning susceptibility may exist, the gender effect is controlled in the
current study. Of course, the use of females in the startle-yawn par-
adigm would be important in future studies, as psychopathy is not a
sex-dependent phenomenon (Anderson et al., 2011). The emotional
component of the PPI-R is likely the most relevant to the experi-
ments herein. While the overall measure is possibly too broad a
measure for these purposes, it nonetheless lends support to the de-
veloping idea that psychopathy, empathy, and contagious yawning
are related.
Appendix A
1
Machiavellian Egocentricism, Rebellious Nonconformity,Blame Externalization, Care-
free Nonplanfulness,Social Inuence,Fearlessness,Stress Immunity,and Coldheartedness.
Table A.1
Standard estimates of factors on contagious yawning.
Predictor βStandard error
Total PCL-R 0.008 0.005
FD 0.015 0.010
SCI 0.001 0.009
CD 0.0620.027
DS
a
1.110⁎⁎ 0.313
Note. PCL-R= Psychopathic check list-revised; FD = Fearless Dominance; SCI = Self Cen-
tered Impulsivity; CD = Coldheartedness; DS = Difference Score of neutral peaks minus
negative peaks.
a
The outcome variable is not dichotomous. The DS predicts frequency of yawning.
pb.05.
⁎⁎ pb.001.
36 B.K. Rundle et al. / Personality and Individual Differences 86 (2015) 3337
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Fig. A.1. Physiologically dened contagious yawn.
Fig. A.2. Contagious yawning frequency observed in participants.
37B.K. Rundle et al. / Personality and Individual Differences 86 (2015) 3337
... Males from the sample (N = 57) also took part in an eyeblink startle paradigm, and consistent with a link to psychopathy, contagious yawning was less common in www.nature.com/scientificreports/ men with a lower startle response 71 . The negative association between contagious yawning and psychopathic traits was also recently examined by Helt et al. 19 . ...
... Drawing from a slightly smaller sample of university students in (N = 97) also from the United States, participants completed the PPI-R, the Autism Spectrum Quotient (AQ), and the IRI (see above). Unlike Rundle et al. 71 , a negative relationship was revealed between the combined PPI-R and video confirmed yawn contagion (yes/no), i.e., participants that scored higher on psychopathic traits were less likely to yawn contagiously, though no analyses were conducted across the subscales of this measure. By employing eye-tracking, the researchers were also able to show that the negative relationship between contagious yawning and scores on the PPI-R was not moderated by visual attention. ...
... Based on the overall mixed findings within the psychological literature, and the relatively limited investigation into the link between psychopathic traits and yawn contagion in particular, the current study aimed to provide resolution to this anticipated association. In particular, this investigation sought to replicate and extend upon the findings from Rundle et al. 71 and Helt et al. 19 , but with a larger and more heterogeneous sample of online participants. Four distinct measures of psychopathy were included to assess the generalizability of this association, and given the importance of physiological variables in influencing yawn contagion (e.g. ...
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Considerable variation exists in the contagiousness of yawning, and numerous studies have been conducted to investigate the proximate mechanisms involved in this response. Yet, findings within the psychological literature are mixed, with many studies conducted on relatively small and homogeneous samples. Here, we aimed to replicate and extend upon research suggesting a negative relationship between psychopathic traits and yawn contagion in community samples. In the largest study of contagious yawning to date (N = 458), which included both university students and community members from across 50 nationalities, participants completed an online study in which they self-reported on their yawn contagion to a video stimulus and completed four measures of psychopathy: the primary and secondary psychopathy scales from the Levenson Self-Report Psychopathy Scale (LSRPS), the psychopathy construct from the Dirty Dozen, and the Psychopathic Personality Traits Scale (PPTS). Results support previous findings in that participants that yawned contagiously tended to score lower on the combined and primary measures of psychopathy. That said, tiredness was the strongest predictor across all models. These findings align with functional accounts of spontaneous and contagious yawning and a generalized impairment in overall patterns of behavioral contagion and biobehavioral synchrony among people high in psychopathic traits.
... In contrast to adults high in psychopathic traits, diminished contagion may appear amongst people with high levels of autistic traits secondary to diminished attention to the faces of others, and in the absence of a background deficit in emotional empathy. Keywords: contagion, autism, psychopathy, empathy, yawn Both Autism Spectrum Disorder (ASD) and psychopathy have been described as empathy disorders (e.g., Platek et al., 2003;Schürmann et al., 2005), and previous research has shown that both individuals with ASD and individuals with high levels of psychopathic traits show diminished eye contact early in life (Robins et al., 2001;Dadds et al., 2014) as well as diminished susceptibility to contagious yawning (Helt et al., 2010;Rundle et al., 2015). At the same time, the clinical presentation of these two disorders is quite distinct, with individuals with ASD being thought to display deficits in cognitive empathy (imagining what someone else might be feeling based on knowing the facts of their situation) and individuals with psychopathy thought to display deficits in emotional empathy (internalizing a small part of the emotions of a person right in front of you, such as laughing more during a movie because the person next to you is laughing, or tearing up during a movie as you watch one of the character's tear up) (Jones et al., 2010). ...
... At a broad level, both individuals with psychopathic traits and individuals with ASD tend to demonstrate diminished emotional empathy. Specifically, both individuals with high levels of psychopathic traits and individuals with ASD have been shown to display reduced physiological arousal to emotional stimuli (Aniskiewicz, 1979;Hare et al., 1991;Patrick et al., 1993;Blair, 1999;Jones et al., 2010;Marsh et al., 2011;de Wied et al., 2012), and reduced emotional contagion (Helt et al., 2010;Rundle et al., 2015;O'Nions et al., 2017). ...
... Several studies have reported non-significant links between susceptibility to yawn contagion and scores on various empathy measures (Haker and Rössler, 2009;Bartholomew and Cirulli, 2014;Gottfried et al., 2015; see Massen and Gallup, 2017 for a review). However, other studies have suggested an association between contagious yawning and some facet of empathy (Platek et al., 2003;Arnott et al., 2009;Rundle et al., 2015). For example, susceptibility to contagious yawning is positively related to performance on cognitive empathy measures, such as Theory of mind tasks, and negatively related to schizotypal traits (Platek et al., 2003). ...
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Both individuals with diagnosed with Autism Spectrum Disorder (ASD) and individuals high in psychopathic traits show reduced susceptibility to contagious yawning; that is, yawning after seeing or hearing another person yawn. Yet it is unclear whether the same underlying processes (e.g., reduced eye gaze) are responsible for the relationship between reduced contagion and these very different types of clinical traits. College Students ( n = 97) watched videos of individuals yawning or scratching (a form of contagion not reliant on eye gaze for transmission) while their eye movements were tracked. They completed the Interpersonal Reactivity Index (IRI), the Autism-Spectrum Quotient (AQ), the Psychopathy Personality Inventory-Revised (PPI-R), and the Adolescent and Adult Sensory Processing Disorder Checklist. Both psychopathic traits and autistic traits showed an inverse relationship to contagious yawning, consistent with previous research. However, the relationship between autistic (but not psychopathic) traits and contagious yawning was moderated by eye gaze. Furthermore, participants high in autistic traits showed typical levels of contagious itching whereas adults high in psychopathic traits showed diminished itch contagion. Finally, only psychopathic traits were associated with lower overall levels of empathy. The findings imply that the underlying processes contributing to the disruptions in contagious yawning amongst individuals high in autistic vs. psychopathic traits are distinct. In contrast to adults high in psychopathic traits, diminished contagion may appear amongst people with high levels of autistic traits secondary to diminished attention to the faces of others, and in the absence of a background deficit in emotional empathy.
... However, a study of incarcerated adult men found no relationship between psychopathy and corrugator mimicry of prototypical anger and sadness expressions [13]. Interestingly, psychopathy in adulthood has been related to reduced contagious yawning [67,68], another process of reproducing another's bodily state that may be related to facial mimicry [69]. Related studies examining the ability to produce prototypical facial expressions have yielded mixed evidence for abnormalities in facial muscle activity in psychopathy. ...
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Meta-analyses have found that people high in psychopathy categorize (or “recognize”) others’ prototypical facial emotion expressions with reduced accuracy. However, these have been contested with remaining questions regarding the strength, specificity, and mechanisms of this ability in psychopathy. In addition, few studies have tested holistically whether psychopathy is related to reduced facial mimicry or autonomic arousal in response to others’ dynamic facial expressions. Therefore, the current study presented 6 s videos of a target person making prototypical emotion expressions (anger, fear, disgust, sadness, joy, and neutral) to N = 88 incarcerated adult males while recording facial electromyography, skin conductance response (SCR), and heart rate. Participants identified the emotion category and rated the valence and intensity of the target person’s emotion. Psychopathy was assessed via the Psychopathy Checklist-Revised (PCL-R). We predicted that overall PCL-R scores and scores for the interpersonal/affective traits, in particular, would be related to reduced emotion categorization accuracy, valence ratings, intensity ratings, facial mimicry, SCR amplitude, and cardiac deceleration in response to the prototypical facial emotion expressions. In contrast to our hypotheses, PCL-R scores were unrelated to emotion categorization accuracy, valence ratings, and intensity ratings. Stimuli failed to elicit facial mimicry from the full sample, which does not allow drawing conclusions about the relationship between psychopathy and facial mimicry. However, participants displayed general autonomic arousal responses, but not to prototypical emotion expressions per se. PCL-R scores were also unrelated to SCR and cardiac deceleration. These findings failed to identify aberrant behavioral and physiological responses to prototypical facial emotion expressions in relation to psychopathy.
... Future research could use objective recording of facial movements (e.g., facial electromyograph) to assess facial movements associated with engaging in laughter. Using this method, prior research showed that individuals high in psychopathic traits are less sensitive to yawn contagion (Rundle et al., 2015). Thus, self-report versus physiologic responses may diverge for laughter contagion in individuals high in psychopathic traits. ...
Article
Introduction Laughter conveys important information that supports social communication and bonding. Research suggests that unique acoustic properties distinguish laughter that promotes affiliation from laughter that conveys dominance, but little is known about potential individual differences in laughter interpretation or contagion based on these specified social functions of laughter. Psychopathy is associated with both affiliative deficits (e.g., lack of empathy and impaired social bonding) and behaviors that assert social dominance (e.g., manipulativeness). Thus, relationships between psychopathic traits and impaired laughter interpretation or contagion could give insight into etiological pathways to psychopathy. Method In two studies conducted with four independent samples (total N = 770), participants categorized laughter clips that varied in cues to affiliation and dominance. Results Participants overall drew rich and accurate social inferences from dominant and affiliative laughter and modulated their interest in joining in with laughter based on the type and degree of affiliation and dominance conveyed. However, individuals higher in psychopathic traits failed to distinguish between laughter types and did not modulate their level of engagement based on laughter features. Conclusion The results suggest a potential mechanism that underlies the broader social difficulties associated with psychopathy.
... Evidence of each of these predictions has been found in humans. Firstly, subpopulations reporting lower levels of empathy, such as children with autism spectrum disorder (ASD) [30] or adults who score highly in psychopathic traits [31], are less likely to engage in contagious yawning. Secondly, both empathy and contagious yawning appear to share a familiarity bias: people experience more empathy for friends and family than strangers and are more likely to contagiously yawn when familiar people yawn [21,24] (but see [32]). ...
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Contagious yawning has been suggested to be a potential signal of empathy in non-human animals. However, few studies have been able to robustly test this claim. Here, we ran a Bayesian multilevel reanalysis of six studies of contagious yawning in dogs. This provided robust support for claims that contagious yawning is present in dogs, but found no evidence that dogs display either a familiarity or gender bias in contagious yawning, two predictions made by the contagious yawning-empathy hypothesis. Furthermore, in an experiment testing the prosociality bias, a novel prediction of the contagious yawning-empathy hypothesis, dogs did not yawn more in response to a pro-social demonstrator than to an antisocial demonstrator. As such, these strands of evidence suggest that contagious yawning, although present in dogs, is not mediated by empathetic mechanisms. This calls into question claims that contagious yawning is a signal of empathy in mammals.
... First, in a study of neural responses to sounds of laughter, thought to be a universal expression of emotion that promotes affiliation and social bonds (Gervais and Wilson, 2005;Scott et al., 2014), CU traits were related to atypical processing of laughter (O'Nions et al., 2017). Second, in adults, higher scores on the coldhearted scale of the PPI-R (i.e., callousness) predicted reduced likelihood of contagious yawning (Rundle et al., 2015), a stereotyped behavior linked to empathy and underpinned by some of the same neurobiological systems involved in affiliation (Platek et al., 2005). These two studies highlight the potential for using more ecologically valid and rich naturalistic expressions of affiliation to better isolate the deficits in affiliative reward or affiliative sensitivity that may underpin CU traits (also see Viding & McCrory, 2019). ...
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Research implicates callous-unemotional (CU) traits (i.e., lack of empathy, prosociality, and guilt, and reduced sensitivity to others' emotions) in the development of severe and persistent antisocial behavior. To improve etiological models of antisocial behavior and develop more effective treatments, we need a better understanding of the origins of CU traits. In this review, we discuss the role of two psychobiological and mechanistic precursors to CU traits: low affiliative reward (i.e., deficits in seeking out or getting pleasure from social bonding and closeness with others) and low threat sensitivity (i.e., fearlessness to social and non-social threat). We outline the Sensitivity to Threat and Affiliative Reward (STAR) model and review studies that have examined the development of affiliative reward and threat sensitivity across animal, neuroimaging, genetic, and behavioral perspectives. We next evaluate evidence for the STAR model, specifically the claim that CU traits result from deficits in both affiliative reward and threat sensitivity. We end with constructive suggestions for future research to test the hypotheses generated by the STAR model.
... Second, a great number of "sexy" and arguably counterintuitive findings have been reported in the psychopathy field. To name only a few recent examples, compared with nonpsychopathic individuals, psychopathic individuals have been reported to be more likely to be night owls (Jonason, Jones, & Lyons, 2013), to use words related to sex and money and less likely to use words related to family and religion (Hancock, Woodworth, & Porter, 2013), to have a poorer sense of smell (Mahmut & Stevenson, 2012), to be less likely to yawn contagiously (Rundle, Vaughn, & Stanford, 2015), to take more selfies (McCain et al., 2016), to exhibit higher face width to height ratios (Anderl et al., 2016), and more likely to be ambidextrous (Shobe & Desimone, 2016). Many of these intriguing results may be genuine. ...
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In response to a crisis of confidence, several methodological initiatives have been launched to improve the robustness of psychological science. Given its real-world implications, personality disorders research is all too important to not follow suit. The authors offer a plea for preregistration in personality disorders research, using psychopathic personality (psychopathy) as a prominent case example. To suit action to word, the authors report on a preregistered study and use it to help refute common misconceptions about preregistration as well as to illustrate that the key strength of preregistration: transparency outweighs its (perceived) disadvantages. Although preregistration will not conclusively settle the many debates roiling the field of psychopathy and other personality disorders, it can help to verify the robustness of empirical observations that inform such debates.
... Second, a great number of "sexy" and arguably counterintuitive findings have been reported in the psychopathy field. To name only a few recent examples, compared with nonpsychopathic individuals, psychopathic individuals have been reported to be more likely to be night owls (Jonason, Jones, & Lyons, 2013), to use words related to sex and money and less likely to use words related to family and religion (Hancock, Woodworth, & Porter, 2013), to have a poorer sense of smell (Mahmut & Stevenson, 2012), to be less likely to yawn contagiously (Rundle, Vaughn, & Stanford, 2015), to take more selfies (McCain et al., 2016), to exhibit higher face width to height ratios (Anderl et al., 2016), and more likely to be ambidextrous (Shobe & Desimone, 2016). Many of these intriguing results may be genuine. ...
Preprint
Full-text available
In response to a crisis of confidence, several methodological initiatives have been launched to improve the robustness of psychological science. Given its real-world implications, personality disorders research is all too important to not follow suit. We offer a plea for preregistration in personality disorders research, using psychopathic personality (psychopathy) as a prominent case example. To suit action to word, we report on a preregistered study, and use it to help refute common misconceptions about preregistration as well as to illustrate that the key strength of preregistration - transparency - outweighs its (perceived) disadvantages. Although preregistration will not conclusively settle the many debates roiling the field of psychopathy and other personality disorders, it can help to verify the robustness of empirical observations that inform such debates.
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The authors tested susceptibility to contagious itching, laughter, and yawning in 55 children with Autism Spectrum Disorder (ASD), ages 8‐14, and 106 typically developing (TD) children, ages 5‐14. Children with ASD were less likely to yawn or laugh contagiously compared with TD peers, but showed increased susceptibility to contagious itching, under naturalistic conditions. Contagious yawning and laughter were positively correlated with emotional empathy in the TD group. In contrast, contagious itching showed no relationship to empathy, and was positively correlated with autism symptom severity in the ASD group. The authors explore the implications of these findings in terms of psychological theories about ASD.
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