**2. Theorical models and empirical findings linking gratitude and well-being**

Several theoretical frameworks have been developed to explain why gratitude relates to well-being. Moreover, empirical studies have consistently shown that gratitude is related to lower levels of psychological distress, higher levels of psychological well-being, and better physical health. Of particular interest are studies evaluating the benefits of gratitude interventions. Gratitude interventions are designed to enhance gratitude through exercises that can be easily practiced and incorporated into one's life (e.g., gratitude journaling, gratitude letter writing).

### **2.1 Why gratitude contributes to well-being**

Why might gratitude contribute to happiness and well-being? The Broaden-and-Build Theory posits that positive emotions like gratitude have an adaptive function that leads to enduring positive consequences [8]. The Find, Remind, and Bind Theory emphasizes that gratitude plays an important role in building interpersonal relationships, which in turn enhances happiness and well-being [9].

The Broaden-and-Build Theory assumes that positive and negative emotions function in different ways [8]. Fredrickson explained that negative emotions, which can occur during moments of danger, produce specific action tendencies such as the urge to attack in response to anger and the urge to escape in response to fear [8]. According to the theory, when danger or threat is present, it is adaptive to narrow one's response options and to select a course of action quickly. In contrast, positive emotions, which do not usually occur under conditions of threat or danger, tend to elicit a broader and more flexible range of thoughts and action tendencies [8]. For instance, Fredrickson suggested that people who are experiencing gratitude may experience the urge to engage in prosocial ways, which can result in a wide range of creative actions [10]. Importantly, responses to positive emotions such as gratitude are likely to be durable and help build

personal resources [10]. The urge to engage in prosocial behavior when one is experiencing gratitude can enhance and strengthen interpersonal relationships and social support systems [10]. Fredrickson noted that positive emotions can also trigger other positive emotions, which can lead to an "upward spiral" in positive affect that improves happiness and well-being [8]. The broadening and building aspects of gratitude and other positive emotions can be transformational for individuals, organizations, and communities [10].

The Find, Remind, and Bind Theory explains how gratitude can strengthen interpersonal relationships [9]. According to this theory, feelings of gratitude serve the important evolutionary function of facilitating the identification of suitable relationship partners by either "finding" a new suitable relationship partner or "reminding" one about the importance of an existing relationship partner [9]. After receiving a benefit, the recipient makes an attribution about the intentions behind the gift and the responsiveness of the benefactor to the person's needs. Feelings of gratitude can lead to improvements in one's perspective about the benefactor and can "bind" the relationship by increasing motivation to engage in relationship strengthening behaviors [9]. Thus, the expression of gratitude is an important component in relationship building.

Both of these theories shed light on how gratitude may improve well-being and why these improvements are likely to be durable. Gratitude changes our thoughts and actions in ways that have lasting benefits and that strengthen our interpersonal relationships. Empirical evidence has provided support for these theories and has revealed many ways that gratitude contributes to well-being.

### **2.2 Research findings concerning the relationship between gratitude and well-being**

Studies have consistently shown that gratitude relates to lower levels of psychological distress. For example, Watkins et al. showed that gratitude was inversely related to depression, physical aggression, resentment, and narcissism [11]. Across three studies, Lin found that gratitude was related to lower levels of depression and suicidal ideation [12–14]. The relationship between gratitude and suicidal ideation was mediated or partially mediated by variables such as self-esteem, psychological well-being, and/or level of depression [12–14]. Petrocchi and Couyoumdijian found that gratitude predicted lower levels of depression and anxiety and concluded that these relationships could be explained by the fact that grateful participants were less critical and more compassionate toward themselves [15]. Sun et al. confirmed that gratitude was inversely related to depression and anxiety and identified cognitive flexibility as a mediator [16]. Taken together, these studies suggest that gratitude may serve as a buffer against negative emotions and suicidal ideation because it promotes an improved perspective of oneself and enhances coping strategies.

Research has also consistently found that gratitude relates to higher levels of positive emotions and well-being. For instance, Watkins et al. found that gratitude was positively related to satisfaction with life, positive affect, and happiness [11]. Wood et al. found that gratitude was positively related to several measures of psychological well-being (e.g., personal growth, positive relationships with others, self-acceptance, purpose in life) after controlling for the Five Factor model of personality [17]. Likewise, Llenares et al., found that gratitude was significantly related to happiness and resilience [18].

### **2.3 Gratitude intervention studies**

Several studies have examined the impact of gratitude interventions on psychological and physical well-being. Two of the most commonly studied gratitude interventions encourage participants to maintain a gratitude journal or to write gratitude letters. Treatment outcome studies for each type of gratitude intervention are described below.

### *2.3.1 Gratitude journal interventions*

Keeping a gratitude journal, which involves recording what one is grateful for, is a frequently studied gratitude intervention. For instance, Emmons and McCullough assessed the effectiveness of gratitude journaling in a series of three studies [19]. In Study 1, undergraduate participants kept a journal once a week for 10 weeks and were randomly assigned to write up to five things they were grateful for (gratitude condition), five things they were hassled by (hassles condition), or five neutral events (neutral events condition). Participants assigned to the gratitude journal condition showed greater optimism concerning the future and evaluated their lives more positively than those assigned to the other conditions. Gratitude journal participants also spent more time exercising and expressed fewer physical complaints than those assigned to other conditions.

The last two studies also evaluated the effectiveness of gratitude journal interventions with some modifications [19]. In study 2, undergraduate participants kept a daily journal for 2 weeks and were randomly assigned to a gratitude, hassles, or downward social comparison condition (i.e., list ways you are better off than others). Compared to other conditions, participants assigned to the gratitude condition showed higher levels of positive affect and increased helping behavior. Unlike Study 1, there were no health or exercise benefits between the conditions. In Study 3, the researchers examined the impact of keeping a gratitude journal on patients suffering from chronic illness (i.e., neuromuscular disease). Participants were assigned to a gratitude journal condition (daily journaling for 3 weeks) or a no-writing control condition. Participants assigned to the gratitude condition showed greater increases in positive affect, life satisfaction, optimism, and sleep quality, and greater decreases in negative affect compared those assigned to the control condition.

Researchers who have used different instructions for gratitude journal interventions and different comparison conditions have also demonstrated beneficial treatment effects. O'Leary and Dockray randomly assigned participants to a gratitude condition (gratitude diary and guided gratitude reflection), a mindfulness condition (mindfulness meditation and mindfulness diary), or a wait-list control condition [20]. Both of the interventions were delivered online four times a week for 3 weeks. Compared to control participants, those assigned to the gratitude and the mindfulness conditions showed reduced stress and depression and increased happiness. While similar effects were seen in both the gratitude and mindfulness interventions, the gratitude intervention led to a larger decrease in stress.

Beneficial effects of gratitude journal interventions have also been found using clinical samples. Kerr, O'Donovan, and Pepping assigned participants who were on an outpatient therapy waiting list to one of two treatment conditions or a placebo control condition [21]. Participants in the gratitude condition kept a gratitude journal and rated the intensity of their feelings of gratitude. Participants in the kindness condition kept a journal of their daily acts of kindness and reported the intensity of their

### *Focusing on Gratitude: Implications for Mental Health DOI: http://dx.doi.org/10.5772/intechopen.107286*

feelings of kindness. In contrast, participants in the placebo control condition simply rated their mood on a daily basis. Compared to the placebo condition, participants in both the gratitude and kindness conditions showed increased sense of connectedness with others, life satisfaction, and optimism, and decreased anxiety. This study provided evidence that maintaining gratitude journals can serve as a helpful activity for individuals who are waiting to receive psychotherapy [21].

Gratitude journal interventions may also have benefits for physical health. Jackowska et al. randomly assigned women working or studying at a university to a gratitude journal intervention, a daily events journal condition, or a no-treatment condition [22]. Participants in the journal conditions completed three entries each week for 2 weeks. Those assigned to the gratitude condition wrote about three things or people they were grateful for, whereas those assigned to the daily events condition wrote about three things that they noticed during the day. Participants in the gratitude condition showed improved optimism, increased positive emotional style, and reduced emotional distress as compared to other participants. Interestingly, they also showed improved sleep quality and had lower diastolic blood pressure compared to participants in the other conditions [22].

As noted in the studies above, gratitude journal interventions have been shown to decrease psychological distress, increase psychological well-being, and improve physical health when applied to various populations such as undergraduate college students, adults suffering from chronic illness, or adults waiting to receive outpatient psychotherapy. Another type of gratitude intervention that is beneficial involves writing gratitude letters.

### *2.3.2 Gratitude letter interventions*

Gratitude letter interventions involve asking participants to write a gratitude letter to a person who has had a positive impact on their life and whose actions they deeply appreciate. In the letter, participants elaborate on how this person has affected their life and why they feel grateful for this person's efforts. Participants are often encouraged to share their letter by reading it to the recipient.

Gratitude letter interventions have been shown to reduce distress and improve well-being. For instance, Toepfer and Walker randomly assigned college students to a gratitude letter condition (participants hand wrote or typed three gratitude letters over the course of 8 weeks) or a control condition (no-writing) [23]. Participants in the gratitude letter condition showed greater increases in happiness and gratitude than those assigned to the no-writing condition. A cumulative positive impact was noted after writing each letter, suggesting that writing multiple letters over time can be beneficial [23]. In a similar follow-up study, Toepfer, Cichy, and Peters randomly assigned college students to a gratitude letter condition (i.e., write three gratitude letters over the course of 3 weeks) or a no-writing control condition [24]. Compared to control participants, those in the gratitude letter condition showed greater happiness and life satisfaction, and less depression.

There is evidence that gratitude letter interventions can be more beneficial than other types of writing exercises. Seligman et al. randomly assigned participants to one of five happiness exercises (i.e., write and share a gratitude letter, record three good things that happened each day, write about yourself at your best, complete signature strengths survey and apply findings, complete signature strengths survey only) or a placebo control exercise (write about early memories) [25]. Participants in all of the happiness exercise conditions showed greater happiness and less depression compared to placebo control participants. While participants writing three good things showed positive benefits for the *longest* period of time, the gratitude letter exercise created the *largest* positive change in happiness and depression reduction compared to other exercises. Follow-up assessments revealed that participants who continually practiced these happiness exercises after the intervention sustained the most gains and were the happiest [25].

Researchers have studied the impact of gratitude letter writing when combined with attention bias modification. Attention bias modification is the process of training an individual to intentionally attend to specific stimuli while ignoring other stimuli [26]. This can be used in a positive manner, also known as positive attention bias modification (PABM), in which disengagement from negative stimuli is promoted to enhance positive emotion states [26]. Gratitude letter writing can be conceptualized as a means of teaching people to attend to positive aspects of the environment, but it does not require ignoring negative stimuli. Stone et al. evaluated the impact of gratitude letter writing separately from and combined with PABM [26]. Participants were randomly assigned to a condition involving gratitude letter writing, gratitude letter writing with PABM training, or a control writing activity and PABM training. Positive affect increased upon completion of gratitude letter writing compared to the control group. These effects were maintained for a longer period of time when gratitude letter writing was combined with a PABM program [26]. Thus, adding PABM training to gratitude letter writing may enhance positive outcomes.

## **3. Gratitude across various situations**

Given the promising findings on the impact of gratitude on well-being, researchers have started to examine specific situations in which gratitude might be particularly beneficial. Below, we briefly review research examining gratitude in the context of the workplace, romantic relationships, and aging.

### **3.1 Gratitude and the workplace**

Researchers have begun to examine how gratitude impacts well-being at work [27]. In a series of three studies, Cain et al. developed and validated a measure of workplace gratitude called the Gratitude at Work Scale (GAWS) [28]. Workplace gratitude was defined as "the tendency to notice and be thankful for how various aspects of a job affect one's life" (p. 441) [28]. Participants rated the frequency they experienced gratitude for various aspects of their job on a Likert-type scale. Exploratory and confirmatory factor analyses produced two subscales: Gratitude for Meaningful Work (e.g., "How often are you grateful for the positive impact your job has on others?") and Gratitude for Supportive Work Environment (e.g., "How often are you grateful for the support you receive from your coworkers?"). Both subscales related to less burnout after controlling for dispositional gratitude and workplace satisfaction. Lanham et al. similarly found that workplace gratitude predicted lower levels of burnout and higher levels of workplace satisfaction after controlling for trait gratitude, hope, and job contextual variables [29].

Researchers have also examined the effects of gratitude interventions on the well-being of employees. For instance, Cheng, Tsui, and Lam examined the impact of keeping a gratitude journal on stress and depression among health care professionals [30]. They randomly assigned employees from five public hospitals to keep a gratitude

### *Focusing on Gratitude: Implications for Mental Health DOI: http://dx.doi.org/10.5772/intechopen.107286*

journal, a hassles journal, or a no-treatment control condition. Those assigned to the journal conditions completed a journal entry twice per week for 4 weeks. All participants completed measures of depressive symptoms and perceived stress at pretest, posttest, and 3-month follow-up. Participants assigned to the gratitude condition showed greater decreases in depressive symptoms and stress over time compared to those assigned to the other conditions. Although the gratitude journal instructions and outcome variables were not specific to the workplace, the study findings were promising because they showed that health care employees can experience improved mental health following completion of a gratitude journal.

Another aspect of life in the workplace that may be impacted by gratitude is civility among employees. Locklear, Taylor, and Ambrose conducted two studies to evaluate the impact of a gratitude intervention on workplace mistreatment [31]. In study 1, they randomly assigned participants to complete a gratitude journal or a daily events journal at the end of each workday over the course of 2 weeks. Participants completed pretest and posttest surveys and nominated a coworker to report on the level of civility exhibited by participants at work. Participants assigned to the gratitude intervention engaged in fewer reported incidents of workplace mistreatment. This effect was mediated by enhancement in self-control resources, which enables people to modify their impulses and workplace behaviors to meet workplace norms [31]. In study 2, the researchers replicated the finding that keeping a gratitude journal lowered reported workplace mistreatment. Mediational analyses showed that the intervention led to an increase in self-control resources, and this effect was stronger for participants who perceived the organization's gratitude norms to be high [31].

Taken together, the evidence that gratitude relates to well-being in the workplace is promising. Interventions such as gratitude journaling have been shown to lower workplace mistreatment and enhance employee well-being. Additional research is needed on the effectiveness of gratitude interventions that are tailored to the workplace. For instance, employees could practice reflecting upon aspects of work they are grateful for and express their thankfulness to coworkers when warranted. Greater understanding of the impact of gratitude interventions on workplace variables such as burnout, employee satisfaction, workplace mistreatment, productivity, and teamwork is needed to help employers decide whether they wish to incorporate these interventions into the workplace.

Importantly, cultivating gratitude in the workplace should not be used as a means of denying or overlooking unjust working conditions or other problems in the workplace. For instance, employees who are not receiving a fair wage or who are experiencing mistreatment at work are not likely to feel grateful and should take action to address these problems. Research should examine whether there are any negative consequences to cultivating gratitude at work such as decreasing motivation to address problems that deserve attention.

Another life situation that may be particularly suited to gratitude is romantic relationships. Below, we discuss research showing that gratitude may be beneficial for romantic relationships because it strengthens the relationship and slows down the process of hedonic adaptation.

### **3.2 Gratitude and romantic relationships**

Research has shown that gratitude in the context of romantic relationships relates to improved relationship quality and relationship satisfaction. Algoe, Gable, and Maisel asked heterosexual couples to complete daily questionnaires every night for

2 weeks that assessed their own and their partner's behavior, how they responded emotionally to their partner's behavior, daily relationship satisfaction, and daily relationship connection [32]. As expected, thoughtful behaviors by a partner from the previous day predicted increases in both feelings of gratitude and indebtedness. However, only feelings of gratitude predicted increases in relationship satisfaction and relationship connection the following day for both members of the couple. The authors concluded that gratitude may boost and strengthen relationships by turning everyday events into opportunities for relationship growth [32].

Gordon et al. used a variety of methodologies across three studies to examine how gratitude impacts romantic relationships [33]. In study 1, undergraduates in a romantic relationship completed a variety of measures of appreciation, partner responsiveness, and relationship satisfaction. Participants who felt higher levels of appreciation reported being more appreciative of their partners and more responsive to their partner's needs. In study 2, undergraduates in a romantic relationship completed measures of appreciation, relationship satisfaction, and commitment each night for 1 week. They were asked to complete follow-up measures 9 months later. Consistent with study 1, participants who felt appreciated by their partner were more likely to feel appreciation toward their partner in return. In addition, appreciation toward a partner was predictive of relationship continuity 9 months later. In study 3, the researchers obtained observer ratings of relationship responsiveness and commitment. Heterosexual members of dating couples from a community sample engaged in a series of videotaped conversations. Participants completed measures of appreciation and independent raters evaluated the couple's interactions for responsiveness, expressions of caring, and partner commitment. Participants who scored higher on appreciation for their partner were rated by observers as being more responsive to their partners and more committed to the relationship. The researchers concluded that feeling appreciated plays an important role in maintaining romantic relationships [33].

The benefits of gratitude for romantic relationships have also been demonstrated through intervention studies. Algoe, Fredrickson, and Gable studied the impact of gratitude expression among heterosexual couples who engaged in a series of videotaped interactions on two occasions with 2 weeks between sessions [34]. During the videotaped interactions involving gratitude, each member of the couple was asked to discuss something kind that their relationship partner had done for them and was given an opportunity to thank their partner. During videotaped interactions of a control task, each member of the couple was asked to describe a positive or negative event that had occurred that did not involve their partner. At least 6 months later, participants completed a survey about their views about the relationship. Perceived responsiveness of partners' expressions of gratitude predicted improvements in relationship satisfaction 6 months later. The authors concluded that this provides evidence for the important role that gratitude plays in strengthening dyadic relationships [34].

Other gratitude expression interventions have similarly shown benefits within romantic relationships. Algoe and Zhaoyang examined the impact of expressing gratitude on personal and relational well-being [35]. They randomly assigned romantic couples to a condition in which they expressed gratitude to their partner or a condition in which they responded to a self-disclosure from their partner. Participants completed measures of partner responsiveness, relationship satisfaction, and life satisfaction at pretest and posttest. Participants assigned to the gratitude condition showed greater improvements on relationship and personal well-being, with the greatest improvement occurring among participants who perceived their partner to be highly responsive.

### *Focusing on Gratitude: Implications for Mental Health DOI: http://dx.doi.org/10.5772/intechopen.107286*

Research has likewise found benefits for gratitude expression among married couples. Kubacka et al. conducted a longitudinal study to examine the role of gratitude in the maintenance of marital relationships [36]. Data on newlywed couples were collected at three points in time over the course of the first 4 years of marriage. Participants completed measures of gratitude and their relationship (i.e., relationship satisfaction, perceived partner responsiveness, relationship maintenance behaviors). Feelings of gratitude in the marriage resulted from their partner's actions to maintain the relationship and the perception of their partner's responsiveness. Gratitude subsequently increased motivation to engage in relationship building actions toward their partner. These effects of gratitude persisted across the four-year data collection period, which highlights the importance of gratitude in relationship maintenance beyond the early stages of the relationship [36]. Similarly, Schramm et al. found that verbal and behavioral expressions of gratitude were associated with higher marital satisfaction and better adaptation among newly married couples [37].

In addition to promoting relationship building behaviors, gratitude may help to minimize hedonic adaptation in relationships. Hedonic adaptation occurs when positive feelings associated with the beginning of a new romantic relationship diminish over time [38]. As Bao and Lyubomirsky noted, gratitude and appreciation help couples to notice and focus on the positive changes that have occurred since the onset of the relationship, savor the positive aspects of the relationship, and lower expectations that more is needed from the partner in order to experience happiness in the relationship [38].

Further research is needed to determine whether gratitude interventions in romantic relationships are ever contraindicated. For instance, in a relationship that involves abusive behavior, could gratitude interventions decrease motivation for an abused partner to leave the relationship or to advocate for changes? Could gratitude interventions be counterproductive for individuals who have difficulty asserting their needs within the context of the relationship? Future research should seek to identify which couples are most appropriate for gratitude interventions.

Aging is another situation in which gratitude may be beneficial. Below we describe studies showing how gratitude can contribute to well-being among older adults.

### **3.3 Gratitude and aging**

Researchers studying gratitude across the lifespan have shown that gratitude can be beneficial for older adults [39]. One aspect of psychological distress for older adults that may be lessened by gratitude is loneliness. Many older adults face limited mobility and increased social isolation, which puts them at greater risk for loneliness. Chui and Diehal examined gratitude and mental health across various age groups (young adults, middle-aged adults, older adults) and found that gratitude was related to less loneliness across all of the age groups [40]. Among older adults, there was a stronger relationship between gratitude and loneliness among men than among women. The authors noted the importance of considering gender differences with respect to gratitude among older adults [40]. Gratitude among older adults has also been shown to be positively related to helping behavior and self-reported health, and inversely related to hostility [41].

Gratitude interventions focused on older adults have yielded promising results. Killen and Macaskill examined the impact of keeping a gratitude journal among adults aged 60 years or older [42]. Participants were instructed to record three good things that happened every day for 2 weeks and were given the choice of selecting

an online or a paper version of the intervention. Participants completed a variety of well-being measures at pretest, posttest, and 1 month follow-up. Participants showed increases in flourishing at posttest, and these improvements were maintained at onemonth follow-up. They also reported lower levels of stress at posttest but this change was not maintained at follow-up. No differences were found in the effectiveness of the intervention based upon delivery method (online versus paper). Interestingly, gratitude scores did not change across the course of the intervention.

In another gratitude intervention for older adults, Bartlett and Arpin assigned participants to a gratitude condition or a control condition [43]. For 3 weeks, participants assigned to the gratitude condition listed three good things that happened each day and described why they happened. In contrast, participants in the control group did not engage in a writing activity. On days participants experienced higher gratitude, they reported less loneliness, greater well-being, and fewer health problems. Furthermore, those assigned to the gratitude condition showed less loneliness and fewer health symptoms over time compared to those assigned to the control condition. Reductions in loneliness helped to explain the relationship between gratitude and fewer health problems.

Researchers have also tested the effects of multi-component gratitude interventions. Salces-Cubero et al. randomly assigned adults ages 60–89 to one of three interventions (gratitude, optimism, savoring) or a no-intervention control condition [44]. All interventions consisted of four sessions offered at a local senior center. Participants assigned to the gratitude condition completed a variety of exercises such as reflecting on gratitude within the past 6 months, sharing about gratitude with other group members, practicing gratitude expression, and enhancing awareness about gratitude. Participants assigned to the other conditions completed a variety of exercises related to optimism or savoring. All participants completed measures of well-being at pretest, posttest, and one-month follow-up. The study found that participants assigned to the gratitude and savoring conditions showed increased life satisfaction, happiness, and resilience, and decreased negative affect compared to those assigned to the other conditions.

Even single-session gratitude interventions can have a positive impact on older adults. Lau and Cheng [45] randomly assigned adults ages 55–85 to a gratitude condition, a hassle condition, or a neutral condition. Participants in each condition were invited to a laboratory and spent 15–20 minutes writing and reflecting upon up to five things they were grateful for (gratitude condition), hassled by (hassle condition), or important life events (neutral condition). Those assigned to the gratitude writing condition showed lower death anxiety compared to those assigned to the other conditions. It is not clear how long reductions in death anxiety lasted because assessment measures were taken immediately after completion of the writing exercise. However, other researchers have similarly shown that gratitude is inversely related to death anxiety [46]. Future studies should explore the extent to which longer gratitude interventions for older adults lessen death anxiety and how long the effects endure.
