1. Running Head: DOGS AND HUMAN STESS
Human Stress Levels and Dog Interaction
Meredith Chatfield
University of Mobile

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Introduction
Every individual experiences varying levels of stress in their daily lives. Unmanaged
stress can lead to numerous psychological and physical health problems- including cardiac arrest.
There are many different stress-reducing techniques and ideas that have been sampled, and in
this study the role of human-dog interaction and its effects on stress levels will be explored.
Pet-therapy has been positively used with managing stress in those who have illnesses
and mental disorders, but little research has been conducted to investigate pet-therapy in healthy
people undergoing a stressful transition in their lives (Adamle, 2009). In a research study of
college freshman on interests of pet therapy at their campus, an astounding 96% of participants
expressed interest in starting a pet therapy program at their university (Adamle, 2009). Because
this was a preliminary study and only quantitative survey data was collected, further research
would need to be conducted to investigate the connections between human stress and dog
interaction. However, the results from this study show a growing interest in pet-therapy, and the
positive results that dogs can have on stress.
After college graduation, most students transition into full-time jobs. Work environments
can be extremely fast-paced and disorganized. In a research study conducted in a service-
manufacturing-retail company, researchers measured cortisol levels (released when distressed) in
saliva of workers throughout the work week when a dog was present or not present in the work
environment (Barker 2010). The majority of participants reported that dogs brought positivity
and relief from work-related stress. The dog group had the lowest cortisol levels- followed by the
no dog group and no pet group (Barker 2010). These results show that there is a correlation
between stress-relief and dogs not only in self-reported data, but also in biological responses
resulting in lower cortisol levels when a dog is present in work environments.

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These researchers published another article that explored the response patterns that buffer
stress when interacting with a therapy dog, after completing a stress test (Barker 2012).
Participants completed the STROOP stress test, followed by a 30 minute period of interaction
with a familiar or unfamiliar therapy dog. This research is important because it shows a
correlation between completing a stressful task and a drop in stress levels after interacting with a
therapy dog, even if the dog is unfamiliar to the participant. A major limitation of this research
was that the STROOP test did not generate high stress responses in participants, making it
difficult to measure the direct impact interaction with a therapy dog had on stress levels (Barker
2012).
It is important to study this topic both in an experimental and observational-exploratory
setting. A team of researchers wanted to explore the question of how to manage increasing
college student stress levels in a non-experimental study (Bell, 2013). A program was started in
the main library at the university, where a therapy dog was placed in an accessible room
throughout the week for students and faculty to interact with. After the visitations, all
participants reported that they would take part in the program again if it was re-opened (Bell,
2013). Although this research is surface-level self-report data, it shows an increasing desire in
the public community to have more pet-therapy programs introduced in common stressful
environments.
Because of increasing interest in pet-therapy, researchers initiated an experiment focusing
on the biological responses exhibited when interacting with a therapy dog (Krause-Parello,
2012). Cortisol and Immunoglobulin A levels were monitored in participants throughout the
study. This study was unique because no stress-provoking simulation was used on participants.
Results showed that pet-owners had higher perceived stress during the experiment, but had lower

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levels of cortisol (Krausse-Parello, 2012). This observation could imply that pet-owners have
adapted lower stress-response patterns from prolonged animal exposure than non-pet owners.
Further research needs to be conducted to support this claim.
Stronger attachment to a pet can influence the mental health on an individual and how
they respond to stressful situations. Pet-attachment was studied rather than pet-ownership in
correlation to mental health in another study (Peacock, 2012). This research revealed that pet-
attachment had the highest connection in dealing with psychological distress than any other
demographic characteristic in participants including; marriage status, job, children, ECT
(Peacock, 2012). These results are valuable in contributing to past research proving that dogs
have an impact on the mental well-being on an individual.
The connection between human stress and dogs was further investigated by using the
Trier Social Stress test (Polheber, 2013). The team of researchers wanted to investigate if the
presence of a companion-animal would cause more stress-relief during the test than the presence
of a human friend. The Trier Social Stress test produced high stress-response levels in
participants compared to research using the STROOP test (Barker 2012). Participants in the
animal-companion group had significantly lower stress levels than any other group. This study
reveals that they are beneficial in stress-management, and are biologically preferred over human-
friends in stressful situations.
There are many ways that companies endorse lower stress-levels in their employees, but
the most effective strategies focus on the individual (Stewart, 2013). Bringing a dog to work is
one of the less-costly options for individual stress-management. A simulated work environment
in another experiment was created using an office-related stress task. It was important that the
researchers limited the time participants interacted with the dog because prolonged physical

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activity can reduce stress levels as well (Barker, 2010). Their results showed that not every
participant had lower stress from the presence of a dog, and future research is needed. Research
in a simulated environment is important because it displays how a dog would impact an actual
work environment and employee stress-levels at their job.
Based on this review of the literature, the presence of a dog significantly lowers stress-
levels in humans when in stressful environments, and people desire more pet-therapy programs
to be available at their work and schools. In the present study, the question that will be explored
is how the role of dog presence effects stress-response levels in a simulated work environment
when completing a stress test. I hypothesize that there will be a significant difference in
biological and self-reported responses in the group with a present companion animal versus the
control group when completing a stress test. This study will take into consideration the
limitations of the past eight articles, and implement measures to avoid these shortcomings for
future research.
Methods
Design
This study will use an experimental design in which there will be a control group that will
not have canine interaction during the computerized stress test, and an experimental group that
will have interaction during the stress test. Salivary samples will be taken before and after the
stress test, heart rate, blood pressure, and self-reported stress levels will also be monitored
throughout the experiment. The independent variable will be the presence of a companion canine
and the dependent variable will be the stress levels of participants. The independent variable will
have two nominal levels: the presence or absence of a companion canine. The dependent variable

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will have two interval levels: increase in self-reported and biological stress response levels, and
decrease in self-reported and biological stress response levels.
Participants
Eligibility Requirements. Participants will be selected from a voluntary sample of
students and faculty at the University of Mobile in Alabama. All participants will complete an
online, demographic pretest that will evaluate pet ownership status and overall attitude towards
dogs. To partake in the study, students and faculty must be between the ages of 18 – 55, in good
health, have reasonably positive attitudes towards dogs, and not have cynophobia (abnormal fear
of dogs).
Recruitment. The study will be publicized through social media and flyers posted
around the university campus. If a person is interested in participating in the study, a website link
will be provided for them to follow and complete the demographic pretest. All students and
faculty that desire to participate should have access to computers on campus to complete the
demographic pretest. The study will be disguised as promoting a potential dog therapy program
that is being researched through the experiment, and participants are needed for a pilot run of the
program to determine if it is successful enough to bring to the university. It is important to use
this deception because if participants knew the purpose of the study and that they would be
taking a stress test, they could alter their behavior to greater control their stress levels,
jeopardizing the results of the experiment. The recruitment period will last 65 days before the
experimental procedure commences. If the participant meets all requirements for the pretest, they
will receive an email containing a link to an informed consent form and further instructions on
when and where the experiment will take place, including contact information for the
Institutional Review Board that authorized the experiment.

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Sampling. Because the University of Mobile is a relatively small student and faculty
population, I predict that there will be a smaller sample size for the study. However, because the
sample is being taken from a University, there will be a wide range of participants from various
demographic backgrounds, which will be beneficial to the purposes of this study.
Incentives. If a participant passes the demographic pretest and is recruited for the experiment,
their name will be entered into a contest to win one of two $30 gift cards to the university gift
shop.
Materials.
Lilly, a therapy dog from a local rehabilitation center will be provided for the experiment.
She will be fully licensed and trained, and her trainer will be present at the location of the
experiment. Blood pressure machines, heart monitors, and salivary cortisol testing devices will
be attained from the university medical center to measure participant’s biological stress response
levels. A stimulated work environment will be created for the experiment by using office
supplies from around the campus.
Procedure.
Following the instructions in the recruitment package, participants will arrive at the
specified building on campus where the experiment will take place. Participants will be
randomly assigned to groups of four specified in their packages and will be given a specific time
to arrive at the experiment. This measure is taken to prevent all participants from being in the
same room, which could increase initial stress levels in some participants. After arriving in the
main lobby of the building there will be a ten-minute rest time in which participants will recline
in a comfortable chair listening to quiet piano music. During this time, heart rate, and blood

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pressure levels will be monitored using the medical equipment provided by the university. When
the ten-minute rest interval has been completed, participants will be asked to sit quietly and not
communicate with each other while they wait for their names to be called to interact with the
therapy dog.
Once a participant has been called into the experimental room, they will be randomly
assigned to the control or experimental group. Before beginning the stress task, they will give a
self-report of their current stress levels to a researcher who will record the information. The
participant will then have 5 minutes to interact and pet the therapy dog. Physical exertion will be
kept to a minimum in an attempt to avoid previous limitations of other studies such as (Barker,
2010). After this period of interaction, both the participant and therapy dog will be led into an
office area were the participant will be asked to complete a computer generated mathematical
task designed to induce stress responses. The researcher will explain that the purpose of the task
is to see how the presence of a therapy dog will affect the stress response levels of the
participant, and if allowing therapy dogs on campus would improve academic performance.
After completion of the stress task, participants will be led out a side door in the office
area into another room were heart rate, blood pressure, and salivary cortisol levels will be
measured again. Another self-report will be taken from the participant to assess their stress levels
during the experiment with a dog present. Participants in the control group will be informed that
the therapy dog needed to leave for a short amount of time to assist another client, and they will
be asked to perform the stress task while the do is not present. Biological response levels and
self-report data will be collected from control group participants in a similar manner. After the
experiment has been completed, a researcher will be waiting outside of the experimental area
with Lilly and her trainer and there will be a debriefing of the purpose of the experiment. The

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group of participants will be able to spend a short amount of time interacting with Lilly and be
given the opportunity to ask her trainer or the researcher any questions they have about the
experiment.
Results
Data will be collected from the medical devices provided by the university and self-report
data from the experiment. All data will be coded and categorized by the experimental and control
groups, and pre-test demographic information. Data will be entered into a Microsoft excel
document, and then into SPSS for further analysis. An independent samples t-test will be used to
examine the relationship between the independent variable (presence of a companion dog) and
the dependent variable (stress response levels). Descriptive statistics will also be collected in
SPSS to examine demographic pre-test data in relation to the results of the experiment.
I hypothesize that there will be a statistically significant correlation between the presence
of a companion dog and biological and self-reported stress response levels after taking into
account the limitations of previous studies including: limiting physical exertion, implementing a
test that results in high stress response levels, and accounting for extreme positive or negative
attitudes towards dogs in participants from the demographic pre-test. I expect that when a
companion dog is present during the stress test, there will be a pattern of decreased self-report
and biological stress levels in the data supporting the hypothesis.
Discussion
A potential limitation of this study is the small sample size that would be taken from the
university, which cannot easily be generalized to the public. In the future, an expanded and more
diverse sample size should be taken to account for the larger population and extensive

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demographic backgrounds. Because this study is unable to be generalized to the public and
cannot necessarily hold true across different people groups and experimental settings, it does not
have external validity.
Another limitation of this study is the limited medical equipment that would be attained
through the university, which could affect the biological results of participants. Although this
measure was taken to preserve money, future studies should invest in more professional and
creditable medical equipment for their experiment. Further longitudinal research is also needed
to fully understand the effects a companion dog has on an individual in a stressful environment
over time. This study was conducted over a short period, which does not accurately reflect the
long-term results of a present companion dog in stressful situations.
Further examination of companion dogs and human stress levels is needed to account for
the limitations of this study. If the hypothesis is supported it would imply that the presence of a
companion dog improves productivity and lowers stress levels in work and school environments.
The study would have internal validity if the hypothesis is supported because the manipulated
variable cause changes in the dependent variable. More animal therapy programs should be
considered in these environments because of their benefits towards individuals both biologically
and emotionally, as this study and previous studies have observed.
Future research can expand the results of this study by researching a broader sample size
and investigating neural activity when a companion dog is present during stressful tasks.
Studying neural activity could be difficult in a stimulated work environment because the
equipment necessary may distract participants or alter their stress response levels while
completing the stress test. Previous studies have focused on biological and self reported stress
levels before and after completing a stress test with a companion dog, but little is known about

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the neural activity that occurs in the brain during a stress test when a dog is present. Studying
neural activity could be a beneficial way to expand this research and further investigate the
effects a companion dog has on human stress response levels.

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References
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Exploratory study of stress-buffering response patterns from interaction with a therapy
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Preliminary investigation of employee’s dog presence on stress and organizational
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Bell, A. (2013). Paws for a Study Break: Running an animal assisted therapy program at the
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Polheber, J., Matchock, R. (2013). The presence of a dog attenuates cortisol and heart rate in the
trier social stress test compared to human friends. J Behav Med 37, pp. 860-867.

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