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J Camosun Psyc Res. (2021). Vol. 3(2), pp. 17-27.
Submitted Winter 2021; accepted July 2021.

How Gratitude Improves the Biological Health and WellBeing of Students
Authors: Michelle Joy Carganilla*
Supervising Instructor: Michael Pollock, Psyc 215 (“Biological Psychology”)
Department of Psychology, Camosun College, 3100 Foul Bay Road, Victoria, BC, Canada V8P 5J2
*Corresponding author email: mjcarganilla@gmail.com

ABSTRACT
In this paper, I sought to understand how gratitude activities could improve the biological
health and well-being of students and decrease the students’ stress-level. Previous research has
found that gratitude increases oxytocin, sleep quality, and activity in the medial prefrontal cortex
and anterior cingulate cortex. In my correlational study, I tested the strength of these
relationships by examining naturalistic daily changes in their variables longitudinally over a twoweek period. I inferred the oxytocin level by measuring my average blood pressure and the
frequency of feelings of caring/sympathy each day, rated sleep quality by the sleep score
recorded in Fitbit after monitoring the sleep each night, determined prefrontal cortex activity by
the score in the PEBL Bivalent Shape Task, and measured gratitude activity by the frequency of
the gratitude feelings each day. Data gathered in my correlational study showed no significant
correlations of gratitude activity with oxytocin level, prefrontal cortex activity, or sleep quality.
The result of this study will serve as guidelines on which substitute methodologies are not
effective in correlating the gratitude activity to the well-being of the students.
1. Introduction
1.1 Research Problem
Students in different parts of the world
face many challenging situations like
examination and school requirements,
financial difficulties, relationships, and
anticipation of what will happen to their
future. These challenging situations increase
the students’ stress-level that affects their
health and well-being negatively. When the
health and well-being of the student are
affected negatively, the student’s motivation
to better himself or herself academically also
decreases. Increased stress-level causes the
students’ immune system to lower which

causes sickness. The decrease in well-being
and health, in turn, causes a lack of energy,
low mood, and mental health issues. Also,
when the health and well- being of students
are affected negatively due to high stresslevel, their drive to pursue their dreams and
passions decreases. I wish to know how
gratitude work could help the students
decrease their stress-level through the
improvement of their biological health and
well-being so their total well-being is at its
optimum while they are pursuing their
dreams.

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1.2 Literature Review
One factor that can improve students'
biological health and well-being is the social
bonding that they form. The research
conducted by Algoe and Way (2014)
provides evidence regarding the biological
effect of expressed gratitude in forming
human bonds in adults. In this study, 77
heterosexual romantic couples who were
part of the larger Carolina Couples Study
were asked to choose something specific
that they felt grateful for in their partner in
their second visit to the laboratory. The
participants were asked to thank their
partner for almost 5 minutes to demonstrate
gratitude, and their partner showed the
receiving of gratitude tasks. Afterwards, the
partners exchanged their role in the activity.
Their saliva was collected after the gratitude
activities and was analyzed for its CD38
content. CD38 is a substance that plays a
role in oxytocin signaling and social
processes. Their study showed that CD38
gene expression is associated with the
quality and how often grateful behaviour is
directed toward a partner. The
polymorphisms of CD38, rs6449182, were
associated with many building blocks on
which gratitude facilitates social bonds. The
consistent pattern in their finding of CD38
and its polymorphism, which indirectly links
the oxytocin system with the quality and
quantity of expressed gratitude, adds to the
growing evidence by which oxytocin may
influence human pair bonds. This study
showcases that expressed gratitude could
increase the oxytocin system activity, which
affects social bond in a relationship.
Another factor that could improve the
health and well-being of people is the
quality of their sleep. Wood et al. (2009)
have conducted a study relating gratitude to
sleep. In their study, participants were asked
to answer questionnaires that measure their

gratitude, pre-sleep cognitions by rating
their thoughts before sleeping, and their
sleep quality using the Pittsburgh Sleep
Quality Index. Their study showed that the
participants' thoughts before sleeping
affected the quality of sleep. In particular,
the gratitude positive pre-sleep cognitions or
the positive thoughts that the subject thinks
before sleeping are positively correlated to
sleep quality (r = .21, p = .001) but
negatively correlated to the negative thought
before sleeping (r = −.11, p = .001). The
result of their study provides evidence that
pre-sleep cognitions affect sleep. In their
research, grateful people think less negative
thoughts before sleeping, which reduces
impairment in sleep. On the other hand,
gratitude increases positive pre-sleep
cognition, which leads to the best sleep
quality. This study shows that grateful
people can improve their health and wellbeing because of the superior sleep quality.
The grateful subjects' brain activity gives
pieces of evidence why gratitude improves
people's health and well-being. In the study
conducted by Kini et al. (2016), recruited
participants doing clinical counselling were
assigned to either a gratitude intervention
group or a therapy-as-usual control group.
The gratitude intervention group participants
were asked to write a letter to someone
expressing gratitude for 20 minutes during
their first, second, and third week of
counselling. Participants in both groups
answered the six-item Gratitude
Questionnaire (GQ), the three-item
Gratitude Adjectives Scale-3, and the
Behavioral Health Measure-20 scale, which
assesses the mental health of the
participants, including anxiety and
depression. Three months after counselling,
participants in both groups underwent fMRI
measurements. The results showed that the
gratitude scores of participants in the
gratitude intervention group showed a
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significant increase after one week of
intervention compared to the therapy-asusual control group (Gratitude = 1.27,
Control = 0.06, t(40) = 2.25, p = 0.015, onetail). However, even though participants in
the gratitude intervention group showed
more significant improvement than the
therapy-as-usual control group in their
Behavioral Health Measure-20 scores, the
results were not significant (Gratitude group
increase = 0.36, Control group increase =
0.17, t(39) = 1.44, p = 0.08, one-tail). The
fMRI results showed that participants in the
gratitude intervention group had increased
activity in the perigenual anterior cingulate
cortex. The perigenual anterior cingulate
cortex is the region of the brain associated
with empathy. Also, participants in the
gratitude intervention group showed a
lasting increase in the pregenual anterior
cingulate responsiveness to gratitude, even
after three months. This study showed that
those who do gratitude activity increase the
neural activity of their responsiveness to
gratitude.
In another study about the brain's neural
activity conducted by Fox et al. (2015),
participants were immersed in the Holocaust
events wherein someone showed them help
as the stimulus. Then they were asked to
reflect and rate afterwards how much
gratitude they have felt in response to the
situation. The brain activity was measured
during the reflection period of the
experiment. The result showed the
Holocaust scenario increased brain activity
in the right occipital cortex, the left superior
frontal gyrus, the left and right caudate, the
left and right temporal pole, the thalamus,
the left superior temporal sulcus and the left
middle frontal gyrus. On the other hand,
when the participants were doing their
gratitude rating, the increased brain activity
was recorded in the medial prefrontal cortex
of both hemispheres, including a cluster

within the frontal pole and the peri-genual
anterior cingulate cortex. The result of the
experiment showed that a region of the
medial prefrontal cortex, specifically the
ventral and subgenual areas, are active when
the participant showed gratitude to gifts
given to them. Social reward and
interpersonal bonding are associated with
activity of the medial prefrontal cortex (Fox
et al., 2015). The Fox et al. (2015) and Kini
et al. (2016) studies provide evidence on
which regions of our brain are active during
gratitude activities.
1.3 Hypotheses
Based on the above literature review, I
predicted the following hypotheses:
• Hypothesis #1: If gratitude activity
increases then oxytocin will increase.
• Hypothesis #2: If gratitude activity
increases then sleep quality will increase.
• Hypothesis #3: If gratitude activity
increases then neural activity in the medial
prefrontal cortex will increase.
2. Methods
2.1 Participant
The author of this paper served as the
sole participant in its studies. The
participant’s age was 38 years old and
identified as a cisgender woman. The
participant was an undergraduate student at
Camosun College who completed the
current studies as an assignment for Psyc
215 (“Biological Psychology”) and chose
this topic due to her interest in the effects of
gratitude on the biological health and wellbeing of students.

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2.2 Materials and Procedure
The researcher performed a correlational
study to test concurrently all of the
hypotheses by examining naturalistic daily
changes in their variables longitudinally.
The participant kept a study journal with her
at all times over this study’s two-week
period in order to record self-observations of
the following four variables: (1) gratitude
activity, (2) oxytocin level, (3) sleep quality,
and (4) prefrontal cortex activity.
To measure the gratitude activity, the
participant recorded in her study journal the
number of times she felt grateful throughout
the entire day by recording in her journal
every time she felt grateful. At the end of the
day, before going to bed she tallied the total
times she felt grateful and recorded it.
To measure oxytocin level, which has
previously been associated with increased
social bonding (Algoe & Way, 2014) and
blood pressure (Petersson et al., 1997), the
participant recorded in her study journal the
number of times she felt caring and
sympathy towards other people and also
measured her blood pressure. The
participant measured her blood pressure
using a digital arm blood pressure monitor.
She recorded her blood pressure three times
a day: in the morning, at midday, and before
going to sleep at night. She then calculated
her average blood pressure for the day.
To measure the sleep quality, the
participant recorded in her study journal her
sleep score after each night’s rest. The sleep
score was monitored by wearing a Fitbit
tracker while sleeping. The overall sleep
score is a combination of the duration of
time spent asleep/awake across the whole
night, how much time is spent in deep and
REM sleep, sleeping heart rate, and
behavioral restlessness. The sleep score
ranges are: 90-100 = Excellent, 80-89 =

Good, 60-79 = Fair, and less than 60 = Poor
(Fitbit, n.d.).
To measure the activity of the prefrontal
cortex, specifically the anterior cingulate
cortex, the participant recorded in her study
journal the score of her PEBL Bivalent
Shape Task which she did at the end of the
day. The PEBL Bivalent Shape task score
includes her response time to identify
incongruent, neutral, and congruent shapes
with its color in pure and mixed conditions.
Also the score comprises her accuracy in
doing the task in incongruent activities in
mixed conditions. The researcher selected
PEBL Bivalent Shape Task as the dependent
measure of speed and accuracy in this task is
associated to the anterior cingulate cortex
activity (Mueller & Esposito, 2014). See the
Appendix for the possible shapes and colors
used in this task.
To assess the strength and statistical
significance of associations between
variables predicted by my three hypotheses,
I performed Pearson product moment
correlations of their predictor variable
(number of grateful activities) with their
outcome variable (oxytocin level, sleep
quality, and prefrontal cortex activity). For
testing Hypothesis #1, I correlated the total
number of grateful activities of the
participant for each day with the
participant’s average blood pressure on
those same days and separately with the
participants frequency of feelings of
caring/sympathy on those days. For testing
Hypothesis #2, I correlated the total number
of grateful activities of the participant for
each day with the participant’s sleep score
the next morning after a night’s rest. For
testing Hypothesis #3, I correlated the total
number of grateful activities of the
participant for each day with the
participant’s score in the PEBL Bivalent
Shape Task. A correlation coefficient was
considered statistically significant if the
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probability of its random occurrence (p) was
< .05 (i.e., less than 5% of the time expected
by chance alone).

prefrontal cortex activity (Hypotheses #1, 2
&3).
4.2 Relation of Results to Past Research

3. Results
As shown in Table 1, gratitude activity
was not statistically correlated with any of
the outcome variables measured in this
study. Oxytocin level, measured by either
diastolic or systolic blood pressure, was not
correlated with gratitude activity (with
diastolic measure: r = -.14, p = .54; with
systolic measure: r = .01, p = .97; see
Figures 1&2). Similarly, oxytocin level,
measured by the frequency of feelings of
caring and sympathy, was not significantly
correlated with gratitude activity (r = .20, p
= .38; see Figure 3). Also, no significant
correlations were found between pre-frontal
cortex activity, measured by the Bivalent
Shape Task score, and gratitude activity (r =
- .33, p = .14; see Figure 4). Finally, no
statistically significant correlation was found
between sleep quality and gratitude activity
(r = -.10, p = .68; see Figure 5). Based on a
comparison of the correlation coefficients,
the pre-frontal cortex activity showed the
strongest correlation with an r of -.33.
4. Discussion
4.1 Summary of Results
Based on previous research, I
hypothesized that increases in three
variables would be due to increased
gratitude activity: the oxytocin level
(Hypothesis #1), the sleep quality
(Hypothesis #2), and the prefrontal cortex
activity (Hypothesis #3). Data from my
correlational study did not support the
predicted relationships of gratitude activity
with oxytocin level, sleep quality, and

The lack of a significant relationship
between gratitude activity and oxytocin level
in the present correlational study is different
from what would be expected based on
previous research conducted by Algoe and
Way (2014). Algoe and Way (2014)
sampled saliva from their participants after
gratitude activities and analyzed it for its
CD38 content. This substance plays a role in
oxytocin signalling and social processes
(Algoe & Way, 2014). In contrast, in my
correlation study I measured the average
blood pressure (diastolic and systolic
pressure) of the participant, based on the
association between oxytocin level and
blood pressure (Petersson et al., 1997), and
also measured the number of times the
participant felt caring and sympathy towards
other people, based on that the ability of
oxytocin levels to affect social bonding
(Algoe and Way, 2014). These methodology
differences could be the reason why the
results of the previous study and my
correlation study differ.
The lack of a significant relationship
between gratitude activity and sleep quality
in the present correlational study is different
from what has previously been reported by
Wood et al. (2009). In the study of Wood et
al. (2009), the participants were asked to rate
their sleep quality using Pittsburgh Sleep
Quality Index. In the correlational study I
have conducted, the Fitbit tracker was used
to measure the sleep quality of the
participant. The Fitbit tracker measures the
overall sleep score based on a combination
of the duration of time being asleep/awake
across the whole night, how much time is
spent in deep and REM sleep, the sleeping
heart rate, and behavioral restlessness. This
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difference in the methodology of how sleep
quality was measured could have resulted in
the different result obtain in the present
correlational study.
The lack of a significant relationship
between gratitude activity and prefrontal
cortex activity differs from what has been
reported in previous research. In the studies
of Fox et al. (2015) and Kini et al. (2016),
the brain's prefrontal cortex activity was
measured using an fMRI scanner, which
could have given them a more accurate way
of measuring prefrontal cortex activity. In
contrast, in the present research, the
researcher has used the PEBL Bivalent
Shape Task as the dependent measure of
speed and accuracy, as Mueller & Esposito
(2014) associated this to the anterior
cingulate cortex activity. These different
methodologies in how prefrontal cortex
activity was measured could have resulted in
their different results.
4.3 Implications of Results
Previous studies on gratitude have shown
positive results on its effect on the wellbeing of people. Although the results of this
research did not show significant results, this
study will serve as guidelines on which
substitute methodologies will not be
adequate to correlate the effect of gratitude
to the well-being of the students.
Furthermore, the results in this study will
serve as guidelines for those who want to
study further the use of the Bivalent shape
task as a measure of the pre-frontal cortex
activity concerning gratitude activity since
the result in this study showed the highest
correlation.
In our society, wherein the stress level is
continuously increasing because of many
challenging situations like the Covid-19
pandemic, finding a way to manage the
stress level would be beneficial to people's

overall well-being. The result of previous
studies showed that gratitude work had
helped lower the stress precursor. In
addition, the result of this research showed a
good relationship between gratitude activity
and pre-frontal cortex activity. Increased
activity in the pre-frontal cortex is a region
of the brain associated with empathy, social
reward, and interpersonal bonding (Fox et
al., 2015 and Kini et al., 2016) that would
help lower the stress level of the students
and improve their well-being.

References
Algoe, S. B., & Way, B. M. (2014).
Evidence for a role of the oxytocin
system, indexed by genetic variation in
CD38, in the social bonding effects of
expressed gratitude. Social Cognitive and
Affective Neuroscience, 9(12), 1855–
1861. https://doi.org/10.1093/scan/nst182
Fitbit. (n.d.). What’s sleep score in the Fitbit
app? Help.fitbit.com. Retrieved March 3,
2021, from
https://help.fitbit.com/articles/en_US/Hel
p_article/2439.htm
Fox, G. R., Kaplan, J., Damasio, H., &
Damasio, A. (2015). Neural correlates of
gratitude. Frontiers in Psychology, 6.
https://doi.org/10.3389/fpsyg.2015.01491
Kini, P., Wong, J., McInnis, S., Gabana, N.,
& Brown, J. W. (2016). The effects of
gratitude expression on neural activity.
NeuroImage, 128, 1–10.
https://doi.org/10.1016/j.neuroimage.201
5.12.040
Mueller, S. T. (2014). Example instruction,
stimulus, and completion screens of the
Bivalent Shape Task (BST). In A. G.
Esposito (Ed.), National Center for
Biotechnology Information, U.S. National
Library of Medicine. doi :10.5334/jors.ak
Mueller, S. T., & Esposito, A. G. (2014).
Computerized testing software for
assessing interference suppression in
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children and adults: The Bivalent Shape
Task (BST). Journal of Open Research
Software, 2(1), e3.
https://doi.org/10.5334/jors.ak
Petersson, M., Lundeberg, T., & UvnäsMoberg, K. (1997). Oxytocin decreases
blood pressure in male but not in female
spontaneously hypertensive rats. Journal
of the Autonomic Nervous System, 66(1),

15–18. https://doi.org/10.1016/S01651838(97)00040-4
Wood, A. M., Joseph, S., Lloyd, J., &
Atkins, S. (2009). Gratitude influences
sleep through the mechanism of pre-sleep
cognitions. Journal of Psychosomatic
Research, 66(1), 43–48.
https://doi.org/10.1016/j.jpsychores.2008.
09.002

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Table 1
Correlation coefficient (r) values, with number of daily trials (n) per correlation in brackets.
Variables correlated
Gratitude activity & oxytocin level
(Diastolic pressure)

r(n)
-0.14(22)

Gratitude activity & oxytocin level
(Systolic pressure)

0.01(22)

Gratitude activity & oxytocin level
(Feeling of caring and sympathy)

0.20(22)

Gratitude activity & sleep quality

-0.10(22)

Gratitude activity & prefrontal
cortex activity
* p < .05.

-0.33(22)

Figure 1
Scatterplot of gratitude activity and oxytocin level measured by diastolic blood pressure.

Oxytocin level- Diastolic pressure
(Average) (mmHg)

86
84
82

80
78
76
74
72
70
0

2

4
6
8
10
12
Gratitude activity (Number of times feeling grateful)

14

16

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Figure 2

Oxytocin level- Systolic pressure
(Average) (mmHg)

Scatterplot of gratitude activity and oxytocin level measured by systolic blood pressure.
120
118
116
114
112
110
108
106
104
0

2

4
6
8
10
12
14
Gratitude activity (Number of times feeling grateful)

16

Figure 3
Scatterplot of gratitude activity and oxytocin level measured by the frequency of feelings of

Oxytocin level- feeling of caring and
sympathy (Number of times feeling
caring and sympathy)

caring and sympathy.
7
6
5

4
3
2
1
0
0

2

4
6
8
10
12
14
Gratitude activity (Number of times feeling grateful)

16

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Figure 4
Scatterplot of gratitude activity and prefrontal cortex activity measured by the incongruent score
on the Mixed trials of the Bivalent Shape Task.

Prefrontal cortex activity- BST
Incongruent score (Mixed) (ms)

1600
1400
1200
1000

800
600
400
200
0
0

2
4
6
8
10
12
14
Gratitude activity (Number of times feeling grateful in a day)

16

Figure 5

Sleep Quality (Sleep score)

Scatterplot of gratitude activity and sleep quality.
100
90
80
70
60
50
40
30
20
10
0

0

2

4
6
8
10
12
Gratitude activity (Number of times feeling grateful)

14

16

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Appendix
The figure shows the possible shapes and colors in the PEBL Bivalent Shape Task (Mueller,
2014).

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