Fear of Wolf and Bear – physiological responses and negative association.
Anders Flykt1, Maria Johansson2, Jens Karlsson3, & Sofie Lindeberg2
1 Academy of Health and Occupational Studies, Department of Social Work and
Psychology, University of Gävle, Sweden
2 Environmental Psychology, Deptartment of Architecture and Built Environment,
Lund University, Sweden
3 Grimsö Wildlife Research Station, Swedish University of Agricultural Sciences,
Sweden
Corresponding author:
Anders Flykt
Department of Social Work and Psychology, Academy of Health and Occupational
studies
University of Gävle
S-801 76 Gävle
Sweden
Phone: +46-26-648574
E-mail: Anders.Flykt@hig.se / ansflt@hig.se
Key words: Fear, Bear, Wolf, IAT, Visual search, SCR, Eye movements, HR
1
Abstract
Participants were fearful of bears, of both bear and wolf, and not fearful of bears or
wolves. Firstly pictures of bears, wolves, moose, and hares were displayed, eyemovements, skin conductance, and ECG were recorded. Secondly participants
decided if a hare picture was present among moose pictures where a picture of a
wolf or a bear could occur. Thirdly, bear, wolf, and hare pictures were sorted with
good or bad words. Independently of fearfulness, bear pictures showed stronger
physiological responding and wolf pictures showed stronger negative association.
The bear fear only group showed somewhat stronger physiological responding to
bears while the bear and wolf fearful group showed more difficulty in associating
bears with good words. When a feared animal occurred during the search task,
response time was prolonged. Fear of bears and wolves seem to be driven by
elaborate cognitive processing rather than by specific fear circuits.
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Fear of Wolf and Bear – physiological responses and negative association.
The probability of humans being attacked by large carnivores in Sweden is at present
relatively small (Linnell et al., 2001), but in a recent survey 44 percent of the individuals
reported that they were afraid of encountering brown bears in the forest and 25 percent
reporting that they were afraid of encountering wolves (Ericsson, Sandström, Kindberg,
& Stoen, 2010). The figures for people with experience of living in areas with wolves and
bears are similar. Forty-two percent of those in areas with presence of brown bear report
fear of encountering brown bear in the forest and 33 percent of those in areas with
presence of wolf report fear of encountering wolf in the forest (Johansson, Karlsson,
Pedersen, & Flykt, 2012). When asked about how fearful they are of attacks of brown
bear respectively wolf, only 30% in both cases said that they feel no fear what so ever.
As fear of wolves and bears is so widespread it affects a large proportion of
humans living in areas with large carnivores and thereby also has a potentially large
impact on decision makers and large carnivore policy. In order to understand and
eventually develop measures to meet human fear of large carnivores it is essential to
know more about the mental processes involved. Up to date no such attempts have been
made regarding fear for large carnivores. Fear of snakes and spiders has been intensively
studied and may provide a useful theoretical framework and relevant comparison.
Despite that there is basically no environmental constraints for everyday life
caused by snakes or spiders, a significant proportion (12 % in females and 3% in males)
of the Swedish adult population is fearful of these animals (see Fredrikson, Annas,
Fischer, &Wik, 1996). Sweden has three species of snakes, adder (Vipera Berus), grass-
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snake (Natrix natrix), and smooth snake (Coronella austriaca), and it is only the adder
that is potentially lethal for individuals with allergic responses to adder poison. Sweden
has no harmful spiders. From an evolutionary theory view point, the explanation could be
that ancestors of humankind would have had a reproductive advantage by acquiring fear
of snakes and spiders fast, without effort, and resistant to extinction (i.e. the preparedness
theory, see Seligman, 1971), it has also been proposed that the visual system in primates
partly has evolved with respect to the presence of snakes (Isbell, 2006). Thus, snakes and
spiders should posses a very specific place in primate information processing, and may
therefore explain the large proportion of reported fear of snakes and spiders. Furthermore,
Seligman (1970, 1971) suggested evolutionary old species, like insects, rats, reptiles, and
birds, to be overrepresented in phobic or subclinical fear. Thus, human fear for mammals
like brown bear and wolf would not be based on the same evolutionary old processing.
Mental processing associated with fear for snakes and spiders have been
intensively researched. Some of the processes addressed have been attentional capture of
the feared animal, (Öhman, Flykt, & Esteves, 2001), dwell time on the feared animal
(Miltner, Krieschel, Hecht, Trippe, & Weiss, 2004; Gerdes, Pauli, & Alpers, 2009)
automaticity of responding to the feared animal (Öhman & Soares, 1994) and behavioral
influences of the feared animal (Sabatinelli, Bradley, & Lang, 2001, see also Flykt &
Caldara, 2006). In order to test for differences between fear for large carnivores and fear
of snakes and spiders, we investigated fear of bear and fear of wolf using experimental
paradigms previously employed in research investigating psychological processing in
participants fearful of snakes and spiders. As the studies investigating fear for snakes and
spider often have used participants fearful of snakes, but not spiders, and the reversed, we
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intended to select participants fearful of bears, but not fearful of wolf (BF), the reversed,
and participants not fearful of neither bears nor wolves (NF). However, did not find
enough individuals fearful of wolves only, instead we managed to recruit individuals
fearful of both wolves and bears (BWF). Reaction times, eye movement data, heart rate
change scores, and skin conductance responses (SCRs) were used as dependent measures.
Picture viewing
Several studies investigating the responses to snakes and spiders in snake or spider
fearful participants have presented the feared animal on a screen for a brief period of
time. The responses evoked by the presentation have been measured and compared
with the presentation of pictures of not feared animals or other stimuli. For example
Öhman and Soares (1993, 1994) recruited participants fearful of either snakes or
spiders and presented them with pictures of snakes, spiders, flowers, and mushrooms.
The common finding was larger SCRs to pictures of the feared animal than other
stimuli. A similar result was obtained for heart rate change scores in a study with
spider fearful, but not snake fearful, women (Flykt & Bjärtå, 2008). In that study
spider pictures was contrasted against five other animal pictures, namely; beetle,
snake, turtle, wolf, and rabbit. The pictures presented in that study covered the full
screen and the picture display in the Öhman and Soares (1993, 1994) studies had a
similar size of stimulus and distance to participant ratio. The perception of the physical
closeness to the threat is related to the physiological response (Lang, Bradley, &
Cuthbert, 1997) according to the predator imminence continuum (see Fanselow &
Lester, 1988). The participants in the Flykt and Bjärtå study showed less deceleration
5
and more acceleration in heart rate changes for spider pictures than the other animal
pictures. This effect occurred even though the participants also had tasks to handle
during the picture viewing. This is important as the vigilance imposed by the task
might be a critical factor for the eliciting of physiological responding.
It has been suggested, based on eye tracking results, that when spiders serve as
task-irrelevant-distractors to spider fearful participants the participants dwell on these
stimuli longer than other task-irrelevant-distractors (Gerdes, Alpers, & Pauli, 2008).
Moreover, Gerdes, Pauli, and Alpers (2009) found that spiders are attended to faster
than other stimuli tested, but that this was a general effect not related to if the
participants were spider fearful or not. However, to our knowledge no study has looked
at gaze direction to a feared animal when that is the only presented item on which it is
explicitly stated that the participants should focus on. With the rationale that a person
can avoid or attend more reliably to a stimulus when there is no alternative stimuli
present (that may distract), it is expected that an effect would depend on the feared
animal.
Visual search
Eye-movement is a complement to other dependent measures in visual search tasks. Eyemovements give information about where the participant is looking and for how long, it
also provides an opportunity to see if the overt attention is dissociated from reaction
times (as shown by Derakshan & Koster, 2011) which are supposed to mirror the
detection time. If snakes and spiders are phylogenic old threats in the evolution of
humans, conscious awareness should not be a necessity for the elicitation of
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corresponding fear responses. Öhman and Soares (1993, 1994) masked pictures of the
feared animal and other stimuli to prevent conscious recognition of the different stimuli,
while measuring SCRs. These experiments showed an elevated SCR to the masked
pictures of the feared animal as compared to other stimuli. This has been interpreted in
terms of automaticity, assisting the conscious controlled processing in the detection of
these potential threats (Öhman & Mineka, 2001). This idea was empirically supported in
a visual search study by Öhman, Flykt, and Esteves (2001). Participants fearful of either
snakes or spiders had the task to detect a deviant stimulus in a search array. The deviant
stimulus could be a snake or a spider among a background of flowers or mushrooms or a
flower or mushroom among a background of snakes and spiders. The results showed
shorter reaction times (RTs) for the feared animal than other deviant pictures, suggesting
a faster detection of the feared stimuli. In another visual search study with participants
fearful or either snakes or spiders Flykt and Caldara (2006) showed larger electrical
activity over the scalp for a deviant feared animal than a not feared animal at a time
window of 500-700 ms after stimulus onset. Flykt (2006) argued that the shorter RTs to
the feared animal might be a consequence of a motor preparation for handling the threat
rather than an effect of early detection. Independent of the origin of this effect, it seems
relatively stable.
To address the question if the feared animal captures attention or attention dwells on the
feared animal Miltner, Krieschel, Hecht, Trippe, and Weiss (2004; See also Lipp &
Waters, 2007) used a modified version of the visual search paradigm with their spider
fearful participants. In one condition the participants had to find a mushroom target
among 15 flower pictures and in another the participants had to find a mushroom target
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among 14 flower picture background and one spider picture (we call this an oddball
distractor). The RTs to the mushroom target for those search arrays that also had a spider
picture in the array were longer than for those without the spider picture. This result
suggests that the spider picture was taking processing resources from the target stimuli.
However, in the Miltner, et al. (2004) study, also eye moments were measured to
investigate the overt attention showing longer scan paths (i.e. time) for a mushroom
target with a spider oddball distractor in the search array than for a mushroom target
without this distractor. This delay supports a longer dwelling on the threat rather an
attentional capture, as was suggested by Öhman et al. (2001). Similar findings and
arguments have been made by Gerdes et al. (2008). Independent of whether the
prolongation of RTs to feared task irrelevant distractor is due to an automatic capturing
(Öhman et al., 2001) or a slowed down disengagement process (Miltner et al., 2004), or a
decrease of inhibition of fear evoking distractors and a reduction of resources available
for shifting attentional focus to the task at hand (Eysenck, Derakshan, Santos, & Calvo,
2007) the visual search results by Miltner et al., (2004) are indicative of fear responding
to a supposedly feared animal. Moreover, it serves as a measure of performance loss due
to exposure to the feared animal.
Implicit association test (IAT)
The implicit association test is based on the assumption that there is strong response
compatibility for pictures, words, and concepts that all are categorized as for example
Good or Bad (see e.g. Greenwald, McGhee, & Schwartz, 1998). Thus, when a word
and a picture are sorted into the same category (e.g. both good or both bad) the
8
requested response will be faster and higher in accuracy compared to a word and a
picture categorized into different categories (e.g. good and bad). Teachman and
coworkers (Teachman, Gregg, & Woody, 2001) showed that in IAT with spider or
snake fearful participants, those fearful of snakes had longer RTs for responding to
snake – good and spider – bad, than for the reversed condition, and that the opposite
was true for those fearful of spiders. In another IAT study by Teachman and Woody
(2003) the spider fearful participants showed longer RTs for the combination spider good than spider - bad combination than the not spider fearful control group. Despite
the fact that there was no difference between these two groups in an IAT task without
spiders. The IAT results by Ellwart, Eni, and Rinck (2006) showed longer RTs to
spider – pleasant words than spider-unpleasant words, and this effect was somewhat
stronger for the spider fearful group than the control group with individuals not fearful
for spiders.
Combining these three experimental paradigms a research quest set out to investigate
how fear of bears and wolves affects physiological activity, performance efficiency,
and associations. Thus, in the present study the participants first got a picture viewing
task, without any additional task, not to risk that behavioral artifacts would obscure
differential physiological responding to the different animal (Moose -Alces alces, Hare
-Lepus europaeus, Wolf, and Bear) pictures. As physiological response is different for
an animal one is afraid of compared to other animal pictures even when all other
stimuli are animals (Flykt & Bjärtå, 2008) we choose to use only animals, and,
moreover, all animals from the same geographic area. We hypothesized that exposure
9
to a feared animal would result in an increased physiological activity, and that eye
movements would differ between a feared animal and not feared animals. The
participants had the task to search for a hare in 3x4 pictures search arrays and decide if
a hare was present or not. The other pictures in the search arrays were moose.
Occasionally a bear or a wolf picture could appear somewhere in the search arrays, but
the participants were instructed to disregard their presence. This is a modified version
of the visual search task used by Miltner and co-workers (2004), with spider fearful
participants, in which it was expected that reaction times for target in search arrays
were prolonged when a feared animal oddball distractor occurred among moose
(Cervus canadensis) distractors. We hypothesized that the presence of a feared
oddball- distractor would prolong RTs as efficiency would be reduced. Moreover, we
also hypothesized that participants would dwell longer on their feared animal, and thus
explain the prolonged RTs. The participants were also presented with four short IAT
tasks. Two of the tasks included bear and hare pictures and two included wolf and hare
pictures, the bear-IAT and the wolf-IAT respectively. In one of the wolf-IAT and one
of the bear-IAT the carnivore required the same response as for good words while in
the remaining wolf- and bear-IAT required the same response as for bad words. We
hypothesized that it would be harder to sort a feared carnivore with good words, than
with bad words, and thus RTs would increase and accuracy would decrease in these
cases. Thus, we expected that both the participants in the bear fear group and the wolf
and bear fear group would have longer RTs, less accuracy, and to look more at the
labels used for the sorting when bear had to be sorted with good words than when
sorted with bad words (and hares with bad words), as compared to the no fear group.
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We also expected that the wolf fearful participants (the group with participants fearing
both bears and wolves) would have longer RTs, less accuracy and to look more at the
labels used for the sorting when wolf pictures where sorted with good words, as
compared to the other two groups (i.e. the no fear and the bear fear group).
METHOD
Method
Participants
Participants were recruited from a survey among people in areas with presence of brown
bear and/or wolves in Sweden. The respondents had, amongst others, indicated if they
were afraid of encountering brown bear or wolf in forest. The participants in the present
study were recruited based on their responses to this survey-item and their indicated
willingness to participate in a follow-up study. Thirty-nine persons accepted to participate
of which 37 did eventually participate, 15 (mean age 58 years SD = 13, 5 women) not
fearful of bear or wolf (NF), 8 (mean age 46 years SD = 14, 6 women) bear fearful (BF),
and 14 (mean age 55 years SD = 16, 9 women) bear and wolf fearful (BWF). The groups
did not differentiate on State-Trait Anxiety Inventory (STAI-T) scores (Spielberger,
Gorsuch, & Lushene, 1970), F<1.
Stimulus materials
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Twelve square color pictures of each of the animal (Bear, Wolf, Moose, and Hare) were
used. The pictures were mostly downloaded from different internet sites and edited to a
square format. The final selection of 48 pictures was rated for how beautiful the pictures
were and how harmless they were perceived. An ANOVA of a rating study with 27
participants showed no difference in how beautiful the pictures were rated, F<1, while
only hare was rated as harmless (4.82), with moose as less harmless (3.66), and wolf
(2.59) and bear (2.68) were rated as low on harmlessness (i.e. rated as harmful), F(3, 75)
= 110.30, p < .01, mse = 0.333, 2 = .82, and Helmert contrasts; Hare vs. later F(1, 25) =
192.78, p < .01, mse = 0.457, 2 = .89, Moose vs. later, F(1, 25) = 66.83, p < .01, mse =
0.405, 2 = .73, and Wolf vs. Bear, F < 1.
Apparatus
The stimulus materials were presented on a 22 in. (56 cm) screen. The size of the arrays
on the screen was approximately 35 cm x 20 cm, and the viewing distance was
approximately 0.8 m. The SMI Experiment Center was used for the stimulus
presentation, collection of eye movements was done with the iView X 250 from SMI and
collection of RTs with a USB numeric keyboard as a response pad was done with the
same software. The electrocardiography (ECG) signal, skin conductance and a signal
indicating the presentations of the stimulus materials were recorded by the BioPac system
(see, e.g., Frazier, Strauss, & Steinhauer, 2004) MP100, with the dedicated software,
AcqKnowledge 3.9 (see e.g., Leong, Mann, Wallymahmed, MacFarlane, & Wilding,
2001), both provided by BioPac Systems (BioPac Systems, Inc., Goleta, CA). The ECG
and skin conductance signals were sampled at 2 KHz.
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Procedure
The participants were contacted by phone. Upon arrival to the lab the participants were
informed about the study, and then signed the informed consent form. Before starting the
experiment a test screen simulating the experimental stimulus settings was displayed to
control for the visual abilities. ECG electrodes were attached (the ground to the neck, the
negative electrode on the right side about 1 dm below the armpit, and the positive
electrode at about the same position on the left side) followed by SCR electrodes that
were attached to the distal phalanx of the first and second finger on the non-dominant
hand. To avoid artifact driven responses the participants were explicitly instructed not to
press on the electrodes. . Participants were then instructed to look at the screen so that the
experimenter could control that the eye tracking camera could detect the eyes (i.e. that the
eyes were at the level of the camera and that the participants eyes were at the right
distance. If not, the screen level and the participants distance to the screen were adjusted
until the camera reliably detected the eyes. The participants were encouraged to move
their heads as little as possible during the experiments.
Experiment 1: Picture viewing
For Experiment 1 the participants were informed that they would look at animal pictures
showing bears, wolves, moose, and hares, and there would be one picture on the screen at
a time preceded by a circle that should be fixated. The participants were instructed to
look at the picture during the entire exposure time. First the eye tracking camera was
calibrated. For this purpose the participants were asked to steadily focus their gaze on a
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white circle that moved across the screen. The same procedure reoccurred as a validation
at the end of the experiment. The exposure time was approximately 4000 ms long. Forty
animal pictures equally distributed for the different animal categories were shown with an
inter trial interval of 10 seconds.
Experiment 2: Visual search
In Experiment 2 the participants were first shown an external USB number keypad used
for response collection and were demonstrated how to hold the keypad with both hands to
be able to respond with their thumbs without pressing the SCR electrodes against the
keypad causing artifact driven responses. Then participants were informed that they
would be presented matrices with 12 animal pictures and these animals could be moose,
hares, wolves, and bears. An example of a matrix (3 row x 4 columns) with only moose
was shown. If a picture of hare was present in the matrix they were instructed to press the
defined response button on the keypad with their dominant hand and that if no hare
picture was present in the matrix they should press another predefined response button on
the keypad with their non-dominant hand. This asymmetry was used because the focus of
interest was on the arrays with a target picture. A second matrix example was shown with
a hare picture among eleven pictures of moose. It was emphasized that it was only if
there was a hare picture in the matrix that they should respond with their dominant hand,
and that they should ignore pictures of wolves and bears. Matrices were exposed for two
seconds and the participants should attempt to respond as fast possible without
jeopardizing the accuracy. The participants were encouraged to try to respond while the
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matrix still was present on the screen. Thereafter the eye tracking camera was calibrated
as described for the picture viewing. Seventy-two matrices with an inter trial interval of
10 seconds were presented. Twelve matrices showed twelve moose pictures, 12 matrices
showed eleven moose pictures and one hare picture, 12 matrices showed eleven moose
picture and one wolf picture, 12 matrices showed eleven moose picture and one bear
picture, 12 matrices showed eleven moose pictures, one hare picture and one wolf
picture, 12 matrices showed eleven moose pictures, one hare picture and one bear picture.
For the later two combinations the placement of the wolf and bear pictures in relation to
the hare picture was counterbalanced. Only target trials were analyzed as the no target
trials were considered filler trials.
Experiment 3: IAT
The participants were instructed that the third experiment would consist of four parts and
that they would be informed by the experimenter before the start of each part. An
example of the screen with a different animal category in each upper corner of the screen
paired with the word good or bad (in Swedish) was displayed to the participants. The
participants were informed that the combination of the category words (e.g. bear good) in
the upper corner of the screen would be shown constantly during the experiment. Then
the participants were informed that a word or an animal picture would occur in the lower
centre of the screen and were shown examples. One example with an animal picture and
one with a word were shown. The participants were instructed that their task was to sort
the animal pictures and the words in accordance with the categories in the upper corners
of the screen. Examples like: If there was a bear picture and the category bear was written
15
in the upper right corner the participant should respond with the predefined response
button on the right side of the keypad. If there was a word like wonderful (in Swedish)
and the category good words was displayed in the right upper corner of the screen the
participant should respond with the predefined response button on the right side of the
keypad. Then the participants were presented to a picture showing a list of good words
and a list with bad words in two columns. The words from these two lists were the words
to be used during the experiment. The information to the participants was repeated until
the participants were confident about their task. The participants were also informed that
before each presentation of an animal picture or a word a white circle would occur
announcing the advent of the presentation. The participants were encouraged to respond
as fast as possible without jeopardizing the accuracy. The eye tracking camera was
calibrated, a first part was run, and validation of the gaze tracking was made. Before the
next part the participants were informed that the animal categories may have changed as
well as that the location of categories in the upper corners of the screen. It was however
emphasized that this new setup would be the same during the entire part. The camera was
calibrated again before the start of the IAT task and validation was made after. The same
procedure was repeated for the remaining two parts. Each part consisted of 32 trials of
which half were animal pictures (equal amount of each animal) and half were Swedish
words (half good – corresponding to; nice, happy, lovely, wonderful, peaceful, excellent,
pleasant, and enjoyable, and half bad words- corresponding to; failure, awful, painful,
evil, mean, terrible, violent, and angry). The order of the four parts was counter balanced.
Inter trial intervals were approximately 4000 ms.
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The experimenter recommended the participants to rest their eyes between each
experiment and between the parts of the IAT task. After the experiments the participants
received a cinema ticket for a movie of their own choice and a certificate of value for a
course on training hunting dogs to track bears or a course on training dogs to ignore wolf
tracks. (Both courses were relevant for people living in the regions where the study was
conducted.) Both courses were given at the Swedish wildlife damage centre. The value
certificates were not personal but could be transferred to someone else.
Data Treatment and Analyses
The peaks of the R-waves were used for the calculation of the interbeat intervals (IBIs).
All trials were visually inspected and artifacts were removed. No attempts to correct for
respiratory responses were made, as the HR was used as an index of orienting response
(OR) and defense response (DR), and respiration is a central aspect of the OR
(Stekelenburg & van Boxtel, 2002). The baseline consisted of the two last entire IBIs
before stimulus onset, and change scores were calculated for the five IBIs following the
IBI containing the stimulus onset. For two participants in the not fearful group HR
change score data from a few trials were deleted as the participants had double-beats and
the difference from one IBI to another became unreasonable (some more than 100 bpm)
these trials were omitted from further analysis as they must be seen as outliers. The
omitted data came from different conditions. Only the correct responses were used for the
analysis of RT data. SCRs were scored semi-manual on screen. Two different measures
of SCRs were used to capture different aspects of sympathetic activity evoked by the
stimulus materials. SCR magnitude was used to establish the average deflection from
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SCL for the largest SCR elicited in the time frame 0.9 to 4 s for the condition, while
number of elicited responses is the number of deflections elicited during the same time
frame per condition. From eye movement data total (i.e. accumulated) length of fixation
and the fixation counts for specified regions of interest were used. The time not captured
by the total length of fixation was time when the eyes moved or when they were fixated
outside the specified areas of interest. All dependent measures were analyzed with
separate ANOVAs for the respective experiments.
RESULTS
Experiment 1: Picture viewing
The 3 group (bear fearful, wolf and bear fearful, not fearful) x 4 animal pictures (bear,
wolf, moose, hare) ANOVA for number of elicited SCRs showed that more SCRs
were elicited to bear pictures than the other pictures, as shown by a main effect of
animal picture, F(3, 102) = 4.61, p < .01, 2 = .12, mse = 1.315, and a Helmert
contrast, F(1, 34) = 9.59, p < .01, 2 = .22, mse = 1.877. The corresponding ANOVA
for SCR magnitude did not show any effect (despite the fact that the picture sequence
was counter balanced across subjects).
The 3 group (bear fearful, wolf and bear fearful, not fearful) x 4 animal pictures
(bear, wolf, moose, hare) x 5 IBI ANOVA for heart rate change scores in BPM only
showed that the BF group had a general decrease in bpm over the five heart beat, while
no such decrease was shown in the other two groups, as shown by an interaction effect
between group and IBI, F(8, 136) = 2.46, p < .05, 2 = .13, mse = 2.42 (see Figure 1).
To control if this difference could be explained by a stronger deceleration to
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their feared animal (i.e. bear), a follow-up analysis was conducted. An Helmert
contrast on a 4 animal pictures (bear, wolf, elk, hare) x 5 IBI ANOVA for heart rate
change scores for the bear fearful group showed tendencies for bear pictures to
generate more deceleration (-1.18) -than wolf (-0.64), elk (-0.60), and hare (-.26)
pictures, F(1, 7) = 2.28, p < .08 (directed hypothesis), 2 = .25, mse = 8.21.
The 3 group (bear fearful, wolf and bear fearful, not fearful) x 4 animal pictures
(bear, wolf, elk, hare) ANOVA for the fixation time showed that the participants had a
tendency to fixate bear pictures (2674 ms) longer than elk pictures (2496 ms) (Main
effect of animal picture, F(3, 102) = 2.73, p = .06, 2 = .07, mse = 91275, and
Bonferroni corrected pairwise comparisons, p = .02). The corresponding ANOVA for
fixation count showed that the participants fixated a larger number of times on bear
pictures (than the wolf pictures). This was shown by a tendency to a main effect of
animal picture, F(3, 102) = 2.44, p < .09, 2 = .07, mse = 90.84, and Bonferroni
corrected pairwise comparisons (p = .03).
These results suggest that pictures of bears are special in that gaze is more often
returned to bears than other animals, the total viewing time then became longer. Bears
also elicit more sympathetic activation as seen as the number of SCRs. Moreover, the
result of the additional analysis of heart rate change scores suggest that bear fearful
individuals are also responding with an increased parasympathetic activity to bear
pictures.
Experiment 2: Visual Search
The 3 group (not fearful, bear fearful, wolf and bear fearful) x 3 oddball distractor type
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(not present, bear, wolf) ANOVA for response accuracy showed that more correct
answers were given for search arrays with a target without an oddball distractor (9.56),
during the two seconds the participants had for their responding, than for the search
arrays that contained an oddball distractor (bear = 8.60 wolf =8.35). This was shown
by a main effect of oddball distractor, F(2, 64) = 8.31, p < .01, 2 = .21, mse = 1.76,
and Bonferroni corrected comparisons (the differences had ps < .01). No other effects
were shown for accuracy.
The 3 group (not fearful, bear fearful, wolf and bear fearful) x 3 oddball
distractor (not present, bear, wolf) ANOVA and subsequent a-priori contrasts for RTs
showed in accordance with the hypothesis that (see Figure 2): The BWF group showed
prolonged RTs to search arrays with an oddball distactor independent if it was a bear
or a wolf. The BF group showed a border line effect for longer RTs to search arrays
with a bear as an oddball distractor than for a search array with no oddball distractor
and search arrays with a wolf as an oddball distractor. Moreover, for this group search
arrays with a wolf distractor resulted in shorter RTs than for search arrays with only a
target and no oddball distractor. The NF group did not show any differences in
response time whether there was an oddball distractor present in a search array with a
target or not. This was shown by a tendency to an interaction between group and
oddball distactor, F(2, 64) = 2.42, p = .06, 2 = .13, mse = 13608, and Helmert
contrasts corresponding to the hypothesis for the group (not fearful group F < 1, bear
fearful group, F (1, 7) = 3.06, p = .06, 2 = .30, wolf and bear fearful group, F (1, 12)
= 8.65, p = .01, 2 = .42).
The 3 group (not fearful, wolf and bear fearful, bear fearful) x 3 distractor type
20
(not present, bear, wolf) of number of skin conductance response (SCRs) showed
more elicited responses to search arrays with a bear as an oddball distractor than when
there was no oddball distractor in the search arrays. This was shown by a main effect
of distractor type F(2, 68) = 4.11, p < .03, mse = 1.948, 2 = .11, and Bonferroni
corrected comparison (p < .01). The corresponding analysis for the magnitude of skin
conductance responses (SCRs) showed no main effects.
The 3 group (not fearful, wolf and bear fearful, bear fearful) x 3 distractor type
(not present, bear, wolf) x 5 interbeat interval (IBI) after stimulus onset ANOVA of
heart rate changes showed that an increase over IBIs (from -0.57 to 0.35), as shown
by a main effect of IBI, F(4, 136) = 8.52, p < .01, mse = 5.95, 2 = .20. Moreover, a
tendency for the BWF group to have a larger deceleration (-1.00) bpm) than for the NF
group (0.60) was shown, F(2, 34) = 3.13, p < .07, mse= 48.51, 2 = .16, and
Bonferroni corrected t-test p < .07.
The 3 group (not fearful, wolf and bear fearful, bear fearful) x 3 distractor type
(not present, bear, wolf) ANOVA of fixation count on the target showed that the
BWF group showed fewer fixations (1.47) on the target than the NF group (2.04). This
was shown by a main effect of group, F(2, 32) = 4.44, p = .02, 2 = .22, mse = 0.280,
and Bonferroni corrected pairwise comparisons (p < .03). The targets presented
without an oddball distractor (1.93) or a bear distractor (1.88) were fixated more often
than targets presented with a wolf distractor (1.66), which was shown by a main effect
of distractor type F(2, 64) = 6.13, p < .01, 2 = .16, mse = 0.109, and Bonferroni
corrected pairwise comparisons (p < .03 and p < .06 respectively).
The 3 group (not fearful, bear fearful, wolf and bear fearful) x 3 distractor type
21
(not present, bear, wolf) ANOVA of fixation time on the target showed that the
target is fixated during longer time if there is no oddball distractor (448 ms) than if it is
a wolf (387 ms). There was also a tendency to fixate the target less if a bear oddball
distractor was present (431 ms). This was shown by a main effect of distractor type,
F(2, 64) = 6.83, p < .01, 2 = .18, mse = 4905, and Bonferroni corrected pairwise
comparisons (p < .01 and p<.06 respectively).
The 3 group (not fearful, bear fearful, wolf and bear fearful) x 2 distractor
(bear, wolf) ANOVA of fixation count on the distractors showed that wolf oddball
distractors were fixated more often (0.89 times) than bear distractors (0.64 times). This
was shown by a main effect of distractor, F(1, 32) = 18.08, p < .01, 2 = .36, mse =
0.055. The 3 group (not fearful, bear fearful, wolf and bear fearful) x 2 distractor (bear,
wolf) ANOVA of fixation time on the distractors showed that wolf oddball
distractors were fixated longer (153 ms) than bear distractors (107 ms). This was
shown by a main effect of distractor, F(1, 32) = 17.93, p < .01, 2 = .36, mse = 1954.
These results suggest that in general the participants spend more time looking at an
oddball distractor when it is a wolf than when it is a bear, while the bear oddball
distractor seems to have elicited the most sympathetic activation. An oddball distractor
reduces the viewing time of the target as compared to when there is no oddball
distractor. That did correspondingly reduce the viewing of the target, which lead to
fewer correct responses (during the postulated time) for search arrays with an oddball
distractor than without.
Experiment 3: Bear-IAT
22
For the IAT tasks that presented bears and hares, a 3 group (no fear, bear fear, or
wolf and bear fear) x 2 sorting of bear (good or bad words) x 2 animal picture (bear
or hare) of the RTs showed that only the BWF group had slower responses when
bear was sorted with good words (871 ms) than with bad words (804 ms) while this
effect was not present in the not fearful (good words 817 ms bad words 830 ms) or
the BF group (good words 813 ms bad words 837 ms). This was shown by an
interaction effect between group and sorting of bear, F(2, 31) = 4.83, p < .02, 2 =
.24, mse = 5832, and subsequent simple contrasts. The corresponding ANOVA for
correct answers during the second available for responding showed that bear
pictures was responded at to a larger extent (5.34 times) than was hare pictures
(4.51 times), as shown by an main effect of animal picture, F(1, 31) = 6.83, p <. 02, 2
= .18, mse = 3.26. This is mainly due to that less accuracy occurs for Hare pictures
when they should be sorted with bad words (3.91- 49%) than when sorted with
good words (5.11 – 64%), this was shown by an interaction effect between sorting
of bear and animal picture, F(1, 31) = 6.61, p < .02, 2 = .18, mse = 1.66.
In a 3 group (no fear, bear fear, or wolf and bear fear) x 2 sorting of bear
(good or bad words) x 2 animal picture (bear or hare) of number of elicited SCRs it
was shown that sorting bear with good words and hare with bad words elicited
more SCRs (1.17) than when categorizing bear with bad words and hare with good
words (0.70). This was shown by a main effect of sorting of bear, F(1, 33) = 5.87, p <
.03, 2 = .15, mse = 1.28. In a 3 group (no fear, bear fear, or wolf and bear fear) x 2
sorting of bear (good or bad words) x 2 animal picture (bear or hare) of SCRs
magnitude it was shown that the BWF group showed smaller responding to bear
23
than hare pictures when sorted bear sorted with bad words and hare sorted with
good words, while no such difference was shown for any other condition. This was
shown by a three-way interaction effect between group, sorting, and animal picture,
F(2, 33) = 3.83, p < .04, 2 = .19, mse < 0.001, and subsequent follow-up tests, t(13) =
2.37, p < .04, d = .0.84.
The 3 group (no fear, bear fear, or wolf and bear fear) x 2 sorting of bear
(good or bad words) x 2 animal picture (bear or hare) for the HR change scores
between the IBI before and the IBI after the IBI with the stimulus onset showed less
acceleration for bear pictures (0.56 bpm) than hare pictures (1.11 bpm) when bear
was sorted with bad words and hare pictures sorted with good words, while no such
difference between bear (1.30 bpm) and hare (0.93 bpm) when bear was sorted
with bad words and hare was sorted with god words. This was shown by an
interaction effect between sorting and animal picture, F(1,33) = 4.98, p < .04, 2 =
.13, mse = 1.44, and subsequent contrasts, t(35) = 2.05, p < .05, d = 0.35, and t(35) =
1.16, n.s.
In the 3 group (not fearful, bear fearful, or wolf and bear fearful) x 2 sorting
categories (bad or good words) x 2 animal (bear or hare) ANOVAs of fixation count
and fixation time it was shown that in the group fearful of both wolves and bears
the participants had a tendency to, fixate more and longer on the area displaying the
words; good words - bears when exposed to bears pictures than good words – hares
when exposed to hare pictures, and on the area displaying bad words – hares when
exposed to hare pictures than bad words – bears when exposed to bears. This was
shown by a tendency to an interaction effect between group, category, and animal
24
for number of fixations of the words supporting the sorting, F(2, 33) = 3.00, p < .07,
2 = .15, mse = 0.184, and for the fixation time, F(2, 33) = 2.79, p < .08, 2 = .15, mse =
6404, and a-priori simple contrasts showing tendencies or differences for the group
fearful of both wolves and bears, while no such tendencies or differences where
show for the other two groups.
These results show that when the sorting does not lead to cognitive
dissonance smaller and fewer responses are elicited than when the sorting leads to
a cognitive dissonance. This effect appears in different measures and sometimes as a
general effect and sometimes as a group specific effect.
Experiment 3: Wolf-IAT
For the IAT tasks that presented wolves and hares, a 3 group (no fear, bear fear,
wolf and bear fear) x 2 sorting of wolf (good or bad words) x 2 animal picture (wolf
or hare) of the RTs only tended to slower responses when wolf pictures were sorted
with good words (862 ms) as compared to whenthe wolf pictures were sorted with
bad words (831 ms), as shown by F(1, 30) = 3.28, p = .08, 2 = .10, mse = 9108.91. No
other effects or tendencies were shown in this analysis. The corresponding ANOVA
for correct answers during the second available for responding complemented the
previous ANOVA by showing that less correct responses for the condition where
wolf should be sorted with good words and hare with bad words, as shown by a
main effect of sorting of wolf pictures, F(1, 30) = 9.81, p < .01, 2 = .25, mse = 6.75.
No other effects or tendencies were shown.
25
In the 3 group (no fear, bear fear, or wolf and bear fear) x 2 sorting of bear
(good or bad words) x 2 animal picture (wolf or hare) ANOVAs of number of
elicited SCRs no effects were shown. Neither was any effect shown by the
corresponding ANOVA for SCR magnitude.
The 3 group (no fear, bear fear, or wolf and bear fear) x 2 sorting of bear
(good or bad words) x 2 animal picture (wolf or hare) for the HR change scores
between the IBI before and the IBI after the IBI with the stimulus onset showed that
the bear fearful group elicited less acceleration to trials with wolf (0.45) than hare
(1.47) pictures, while the BWF group tended to elicit more acceleration to wolf
(0.85) than hare pictures (0.57). No such differential responding was shown in the
NF group (1.07 vs 0.95). This was shown by a interaction effect between group and
animal, F(1,33) = 4.98, p < .04, 2 = .13, mse = 1.44, and subsequent contrasts, t(7) =
2.79, p < .03, d = 1.03, t(13) = -1.83, p = .09, d = 0.26, and t(13) = -0.50, n.s.
respectively.
In the 3 group (not fearful, bear fearful, or wolf and bear fearful) x 2
categories (bad or good words) x 2 animal (wolf or hare) ANOVA of fixation count
it was shown that in the BWF group the participants had a tendency to fixate fewer
times on the area displaying the words; bad words - wolves when exposed to wolves
pictures than bad words – hares when exposed to hare pictures. Also the BF group
tended to do this. The latter was shown by a tendency to an interaction effect
between group, category, and animal for number of fixations of the words
supporting the sorting, F(2, 33) = 2.61, p < .09, 2 = .14, mse = 10.93, and a-priori
26
simple contrasts showing a differences for the BWF group (p< .02), and a borderline
effect for the BF group (p<.06).
In the 3 group (bear fearful, not fearful, wolf or bear fearful) x 2 categories
(bad or good words) x 2 animal (wolf or hare) ANOVA of fixation time it was shown
a general effect of shorter average time fixating the area displaying the words; bad
words – wolves when exposed to wolf pictures than any other word area included in
the analysis. This was shown by an interaction effect of category and animal, F(1,
33) = 8.46, p < .01, 2 = .20, mse = 3332.03. The interaction effect also explains the
main effect of category F(1, 33) = 12.62, p < .01, 2 = .28, mse = 3332.03, and the
tendency of animal F(1, 33) = 3.82, p < .06, 2 = .10, mse = 1892.69. No other effects
or tendencies were shown.
Overall also these results suggest that congruence results in less responding,
while dissonance results in more, like for the Bear IAT. Wolves seems however to be
a less potent stimuli for eliciting these responses than bears are.
Discussion
Due to the complexity of the results (see Table 1) the discussion is divided into four
parts. Each of the three first parts restates and discusses the main results from each
paradigm. The last part is a general discussion, that integrates results from the
different paradigms and addresses them in relation to fear of snakes and spiders.
Moreover, the indentified differences between fear of bear and fear of wolf is
discussed.
Discussion of Picture viewing results
27
In the picture viewing most SCRs, most eye fixations, and the longest eye fixations
were shown for bear pictures. Moreover, the BF group showed a deceleration to
bear pictures. Bear pictures seems to be potent stimuli for eliciting physiological
responding independently of whether or not the participants were selected to be
fearful or not fearful of bears. The HR deceleration shown to bear pictures by the BF
group (but not by the BWF group) can be interpreted in two different ways. One is
that, in areas where brown bear occur (mainly the northern hemisphere), fear for bears
is a more rational fear than fear for snakes and spiders. Fear for snakes or spiders
elicit more acceleration of heart rate to pictures of the feared animal as compared to
not feared animals (see e.g. Flykt & Bjärtå, 2008). The larger deceleration of heart
rate to bears in the BF group is contrary to results from snakes and spider fearful
persons (see e.g. Flykt & Bjärtå, 2008), but may be indicative of deployment of
attentional resources (Graham, 1992) directed towards the threat (i.e. the bear).
This could be related to a need to keep track of movement directions of the bear. In
this situation decelerating heart rate response may even be functional by to avoid a
bear attack (Herrero, 2006). Another explanation would be that in the corresponding
research with snake and spider fearful participants the imminence of the
threatening animal is supposedly high with an enlarged spider or snake picture
display. In the present study the size of the bear corresponded to seeing a bear at a
distance. Thus, the difference in direction of HR change (deceleration for bears in
bear fearful and acceleration for e.g. spiders in spider fearful) could in the light of
Fanselow and Lester’s (1988) etiological model of defense behaviors and perceived
distance to predator be due to a difference in predator (threat) imminence.
28
Accordingly the bear pictures triggering a post-encounter defensive behavior response
(i.e. freezing) related physiological activity (HR deceleration), while the spider and snake
pictures triggering a circa-strike defensive behavior response (escape) related
physiological activity (HR acceleration). Post-encounter defensive behavior is related to
HR deceleration and circa-strike defensive behavior is related to HR acceleration is
supported by a proposed model for human physiological responding in relation to threat
imminence from the Lang research group (Lang, Bradley, & Cuthbert, 1997).
Discussion of Visual search results
In the visual search task fewer correct responses were shown for search arrays
containing an oddball distractor, and there were more and longer fixation on the
wolf distractors. Most SCRs were elicited to search arrays with bear oddball
distractors. Longer RTs were shown to search arrays with a feared distractor.
Moreover, the BF group also showed faster responses to the target (i.e. a hare
picture) for search arrays with a wolf oddball distractor than for targets in search
arrays without any oddball distractor. The BWF group showed fewer fixations on
the target. The only effect that showed a clear association between animal fear and
the feared animal in the present study was the prolonged RTs to the hare targets
when a feared animal was present in the search arrays (see Miltner et al., 2004).
Less fixations on the targets was only shown in the BWF group. However, no fear
specific increase of fixation on the feared animal was shown. The RTs effect was a
replication and extension of the finding with prolonged RTs to a spider oddball
distractor for spider fearful participants (see Miltner et al., 2004). Furthermore,
29
shorter RTs to targets were shown for the BF group when a wolf oddball distractor
was present in the search array. This somewhat surprising result might shed some
new light on the processing that occurs in visual search tasks with feared animals
(see e.g. Öhman et al., 2001; Miltner et al., 2001; Flykt & Caldara, 2006). It seems like
attention not only dwell on the feared oddball distractor, but that an odd ball
distractor not consisting of the feared animal could enhance the processing of the
target present response. One reasonable explanation is that a wolf oddball
distractor serves as a safety signal for the bear fearful group. A parallel is the control
stimulus (CS-) in differential classical conditioning that never follows by the
unconditioned stimulus (UCS) to ensure that the increase in responding to the
conditioned stimulus (CS+) is due to an associative learning effect and not a
sensitization effect. The magnitude of responding to CS- tends to decrease over time
as the participants understand that the CS- signals that no UCS will follow (see e.g.
Lovibond, Siddle, & Bond, 1993, Figure 1, lower left panel, the conditioning phase).
We argue that the bear fearful participants will be more efficient in their response
as they know that they will not suddenly see their feared animal. In other words no
worries of encountering the feared animal are imposing on the available resources,
so that those could be more efficiently used. This result has implication for the
attention control theory (Eysenck et al., 2007). which suggests that cognitive
inhibition of task irrelevant information is decreased when such information is a
fear eliciting stimulus. This would be due to that the feared stimulus drives a
bottom-up process suppressing cognitive inhibition. The theory also suggests that
shifting of resources between tasks is harder when exposed to a fear elicitin
30
stimulus. Our finding with faster RTs to a target when a not feared oddball animal
distractor is present adds to the attention control theory (Eysenck et al., 2007). That
is, our results suggest that the mere possibility that a fear eliciting stimulus could be
present decrease the cognitive inhibition. This decrease in cognitive inhibition is not
caused by the actual threat but caused by the vigilance induced by the potential
appearance of this threat. In other words, our finding suggests that; the mere
knowledge that a threat could appear decreases cognitive inhibition.
That RTs are prolonged to target with a feared oddball distractor present in
the display but that the measures of overt attention (i.e. eye movements) did not
show a corresponding effect further support cognitive processing. That is, previous
results from visual search with spiders and snakes as feared animals have been
interpreted as faster detection (Öhman et al., 2001), longer dwell times (Miltner et
al., 2004), and motor preparations (Flykt & Caldara, 2006; Flykt, 2006) cannot be
the full explanation for visual search with wolves and bears. Instead we suggest that
fear for large carnivores, to a large extent, is due to a cognitive process that is rather
elaborated. That fear for bears and wolves would be driven by a specific fear
module, as has been suggested for fear of snakes and spiders (Öhman & Mineka,
2001), is not supported by our visual search data.
Discussion of IAT results
In the bear-IAT the number of correct responses decreased when hare pictures had
to be sorted with bad words. Furthermore, more SCRs were elicited when bear
pictures had to be sorted with good words. When bear pictures had to be sorted
31
with bad words less HR acceleration was shown than when hare pictures had to be
sorted with good words. Moreover, the BWF group showed longer RTs to sort bears
with good words, larger SCR magnitude when bear pictures were sorted with good
words, and showed more and longer fixations to the bear/good and hare/bad word
pair displays than to bear/bad and hare good word pairs displays. These results are
in line with the IAT-results for snake and spider fearful participants that had to sort
pictures of their feared animal with good words resulted in longer RTs (Teachman,
Gregg, & Woody, 2001; Teachman, & Woody, 2003). However, these effects
indicating cognitive dissonance are not shown in the BF group.
In the wolf-IAT all groups showed longer RTs, fewer correct responses for
wolf-good and hare-bad than for wolf-bad and hare good trials and longer fixations
to the earlier word pairs. This general result indicated a general negative
association to wolves independently of being fearful of wolves or not. Similar results
were found with spiders (Ellwart, Eni, & Rinck, 2006).
These general effects are related to cognitive dissonance. As the IAT supposedly is
related to attitudes (Greenwald et al., 1998) based on associations it might suggest that
the BWF group has a general strong negative association to large carnivores that
makes the sorting of these animals even harder than for the other two groups. They
do for example have to confirm the sorting by looking at the cognitive dissonant
word pairs used for the sorting more frequent and sometimes also longer.
Moreover, this was also associated with larger SCRs in the bear-IAT.
General discussion
32
The present results bring new and important insights for the human dimension of
wildlife management. In comparison with snake and spider fear, bear and wolf fear
seems to differ extensively. First and most important, in the present study the HR
changes and SCRs do not reliably discriminate between the feared animal/s and the
not feared animal as would been expected from studies with snakes and spiders (e.g.
Öhman & Soares, 1993, 1994; Flykt & Bjärtå, 2008). The only differential HR
responding was for bear pictures versus other animal pictures in the BF group. No
such were shown for the BWF group, suggesting that fear for bears has different
qualities in the two different groups, and thereby different etiologies. It might be
that BWF group could be compared with the spider fearful (Flykt & Bjärtå, 2006)
and the snake or spider fearful participants (Öhman & Soares, 1993, 1994) in
previous studies as a spider fearful participant was selected based on the low fear of
snake and a snake fearful participant selected based on low fear of spiders. We
know of no study where the participants have been selected to be fearful of both
snakes and spiders. When looking at the visual search results these neatly show a
replication of the Miltner, et al. (2004) results, and the present results do not
suggest that fear responding is different due to the selection of participants fearful
of both bear and wolf. The group selected to be fearful of both bears and wolves
showed responses in the bear - IAT that would be expected from spider or snake
fearful participants exposed to spider an snakes, respectively, in IAT (Teachman,
Gregg, & Woody, 2001; Teachman, & Woody, 2003). However, the group selected to
be only fearful of bears did not show such effects in the bear-IAT. Thus, suggesting
33
that the fear for bears may have different etiologies if only fearful of bears or fearful
of large carnivores in general.
The results from the present study indicate a general tendency for bear
pictures per se to result in more physiological responses as well as more and longer
fixations when the only task participants was to look at the pictures. Similar general
results for eye movements have also been shown for spiders (Gerdes, Pauli, &
Alpers, 2009). Thus we suggest that bear pictures are potent stimuli that elicit
physiological responding and more overt attention demands in a large majority of
people. This activation would then be largely unrelated to if the individual report
being fearful or not. It is reasonable to think that among participants in the BF group
only the physiological responding elicited by bears is associated with an experience
of fear. In other words, the physiological responding is appraised as part of a fear
reaction in those fearful of bears only, while others do not make the similar
appraisal. For the BWF group fear of bears seems to have a somewhat different
ground. Instead of appraisal of physiological responses to bears it seems that in this
group negative associations are the core of fear. The dissonance between good
words and bears is larger for participants in the BWF group, than for participants in
the BF group and the NF group. The cognitive dissonance in those fearful of both
bears and wolfs is appraised as fear. Thus, fear of bears and wolves seem to be
driven by elaborate cognitive processing rather than by evolutionary old dedicated
systems for fear responding.
Wolves are associated with negative words among a majority of people, wolf
pictures do not elicit more physiological responding in tthe BWF group, than among
34
the other participants. Therefore, it seems reasonable to suggest that in those fearful
of bears and wolves the negative associations have been appraised differently than
for those not fearful of wolves. It also indicates that the etiology of fear of bears and
of wolves do not differ much in those fearful of both animals, but that fear for
wolves and fear for bears in those only fearful of bears differs despite that both are
suggested to have a cognitive origin. Such explanation is supported from different
fits to a path model of fear for bears and wolfs on questionnaire data done by this
research group (Johansson, Karlsson, Pedersen, & Flykt, 2012). One limitation of the
present results is the low number of participants in the BF group. The small sample
size might results in effects that, as a matter of fact, are present in this population do
not show. That is, an effect obtained for the BWF but not for the BF group might be
due to a lack of power. However, the difference in physiological responding
between the groups was based on the presence of an effect in the BF group, but not
in the BWF group. It would be hard to argue this is a result of the small sample size.
Despite that some differences might be due to type II errors in the group only
fearing bears, the differences shown based on an effect in the group only fearing
bears but not in the group fearful of both animals strongly suggest a difference
between these two groups. It is, indeed, important to emphasize that the etiology of
fear for bear may differ depending on if the individual only fear bears or other large
carnivores as well, as this can have direct consequences for wildlife management.
Future research has to address this question with great care as one specific
intervention might give opposite results in two groups with different etiologies.
35
Fear of bears and wolves seem to be driven by elaborate cognitive processing rather
than by evolutionary old dedicated systems for fear responding.
36
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