Positive Psychology

Abstract

Psychology is often focussed on disorder, disability, and disease, instead of resilience,

recovery, and well-being. Positive Psychology aims to shift the perspective to what goes

right, and one way towards improved happiness, is through Positive Psychology Interventions

(PPIs), such as the Three Good Things (3GT) gratitude intervention. The present study aims

to build upon PPI research by asking the question ‘Does practising gratitude improve

happiness through a PPI?’. A two-week 3GT intervention was conducted in a single-

participant pre-test-post-test design. Results indicated improved happiness levels at one and

two weeks post-test. Implications include the effectiveness of a gratitude practice in

improving levels of happiness, and that the success of PPIs is supported, especially in terms

of gratitude interventions.

Does practising gratitude improve happiness through a PPI?

Positive Psychology, founded by Martin Seligman (1998), emerged as a movement

away from traditional, clinical psychology and its focus on disorders, disability, and disease.

Instead, while applying mainstream psychology’s scientific and methodological strengths,

positive psychology is a development aimed at resilience, recovery, and well-being (Carr,

2022). According to Seligman (2005), the focus on what is wrong in life tends to overshadow

what goes right in life (Seligman et al., 2005). In other words, there is a focus on what is

wrong and what could be done to restore the damage, rather than apithology, referring to a

focus on what is right and what could be done to increase positive experiences (Kristjansson,

2010). However, removing suffering, does not automatically result in a happier individual,

but rather an empty one (Seligman et al., 2005). Therefore, the aim of Positive Psychology,

and the way to a happier individual, is not only through the absence of misery, but rather the

improvement of encouraging life circumstances (Seligman, 2010).

To many people, the goal of happiness, or its closely related, arguable equivalent,

subjective well-being, (Andriani & Lukman, 2023) is worth striving towards, as it is often

both the reason for and result of several advantageous effects such as in health, marriage, and

career settings (Sin & Lyubomirsky, 2009). Historically, well-being was understood from a

religious point of view through faith, writings and revelations, or more philosophically,

through rational argument (Carr, 2022). Earlier, more modern perspectives describe

happiness as a combination of life satisfaction, positive affect, referring to pleasant emotions,

and negative affect, referring to unpleasant emotions (Schiffrin & Nelson, 2010). However,

Seligman (2002) proposed a more contemporary definition of happiness that includes the

pursuit of three core ideas: The pleasant life through positive emotion experiences, the

engaged life through engagement in activities, and the meaningful life through finding

meaning and purpose in life (Schiffrin & Nelson, 2010). Later, Seligman even extended his

theory to include accomplishment and positive relationships in his description of what makes

individuals flourish (Proyer et al., 2017). Together, positive emotion, engagement, positive

relationships, meaning, and accomplishment formed the PERMA model of well-being (Carr,

2022).

Therefore, in order for individuals to be able to function in an optimal state of well-

being, it is important to know how this is achievable (Sin & Lyubomirsky, 2009). Based on

research of Peterson and Seligman (2004, as cited in, Killen & Macaskill, 2015) well-being is

consistently associated with six virtues composed of and supported by 24 character strengths.

A character strength that is viewed as an essential aspect of well-being, and is categorised

under the virtue of transcendence, is gratitude (Killen & Macaskill, 2015).

Gratitude is also regarded as a successful coping mechanism, as individuals who

foster it, tend to view life as a gift, are more likely to seek the positive side of a difficult

situation, and change their perspective towards what is really important in life (Emmons &

McCullough, 2003, as cited in Andriani & Lukman). It is suggested that gratitude also

promotes individuals’ prosocial and interpersonal behaviours, leading to stronger positive

affect and greater well-being (McCabe et al., 2011). Therefore, contemporary research has

opened the door to a practice of and focus on gratitude as a way to increase happiness

(Lyubomirsky et al., 2005, as cited in, McCabe et al., 2011).

One promising way towards such a happier life is through Positive Psychology

Interventions (PPIs). PPIs are suggested to be effective in boosting happiness and subjective

well-being (Bolier et al., 2013). These exercises aim to encourage positive behaviours,

cognitions and emotions (Sin & Lyubomirsky, 2009), and one of the most well-known

gratitude interventions is the Three Good Things (3GT) intervention. The Three Good Things

is also considered to be an intervention that indicates some of the most significant and long-

lasting effects (Proyer et al., 2014). This practice of gratitude encourages individuals to notice

daily positive occurrences that might normally be overlooked (Sexton & Adair, 2018).

Rash et al. (2011) explored the effects of a gratitude contemplation intervention on

65 adults’ well-being over an implementation period of four weeks. A memorable events

condition served as the control. The gratitude contemplation intervention required

participants to ponder on people, experiences and objects individuals were grateful for, twice

a week, for four weeks. Participants were also asked to journal about these things after

pondering on them. In the control condition, gratitude was replaced by memorable events.

Results indicated that, compared to the control group, participants who practiced gratitude,

revealed increased self-esteem levels and improved satisfaction with life. However, Rash et al

(2011) suggested that the gratitude contemplation intervention may yield more desirable

outcomes for those who exhibit relatively low levels of gratitude.

Moreover, more closely in line with the present study’s focus, Seligman et al. (2005)

conducted a six-group random-assignment placebo-controlled online study that investigated

the effects of five happiness interventions and one control activity, on happiness levels. One

of the five interventions was the Three Good Things (3GT) intervention where participants

were asked to write down three things that went right and what lead to them, nightly for a

week. Based on both its simplicity (Cunha et al., 2019) and effectiveness (Proyer et al.,

2014), this intervention will also be implemented in the present study.

A total of 411 middle-aged adults completed the full experiment, including follow-up

measurements one week, one month, 3 months and six months after the interventions. In

order to measure all three aspects of happiness, including the pleasant life, the engaged life,

and the meaningful life, as well as their symptoms, the authors created the Steen Happiness

Index (SHI). The SHI is also designed to be sensitive to, especially upward changes in

happiness. Results revealed that the Three Good Things exercise increased happiness in that

participants were happier a month later than they were at the start of the experiment. These

effects were still present at the follow-up stages three-months and six-months later, however,

these lasting results may be explained by the fact that the majority of these participants

voluntarily continued the activity on their own, and therefore, only one week might not be

sufficient for enduring effects of the 3GT intervention (Seligman et al., 2005). To test the

suggestion of a longer intervention, the current study will employ the 3GT for two weeks.

Furthermore, in a replication study, Mongrain and Anselmo-Matthews (2012) found more

subtle results and ascribe it to the fact that Seligman et al.’s (2005) participants were recruited

as readers of his book, and therefore these individuals were possibly much eager to become

happier than another sample.

Another study by Proyer et al. (2014) also explored the long-term effects of

interventions, such as the Three Good Things, in an online environment. They wanted to

evaluate the effectiveness of a one-week Three Good Things exercise in older participants

aged 50+, and hypothesised that the intervention would be successful in improving happiness

as it is shown to be the case for younger individuals. The Authentic Happiness Inventory

(AHI) was used for pre-test and post-test measures a week later, as well as follow-up

measures one, three, and six months later. The AHI is described as being more attuned to

slight changes in happiness levels compared to alternative measures Proyer et al. (2014), and

therefore the present study will also make use of this scale. Unexpectedly, the 3GT

intervention only delivered subtle significant effects at immediate post-test compared to the

control. At no other stage were these results more significant than that of the placebo control.

The brief intervention period might account for the short-lived effects on happiness and as

mentioned previously, the current study will extend the intervention duration time.

Similarly, Sexton and Adair (2018) evaluated the efficacy of a 15-day long

intervention of the Three Good Things on well-being, focussing on female healthcare

workers struggling with a work-life balance and burnout. The intervention required

participants to write about what three things went well that day, what they did to make it

happen, and a positive emotion that accompanied each good thing. The present study will

take on the same approach to the 3GT, as it encourages a more descriptive account of daily

wins. The participants’ in Sexton and Adair’s study subjective well-being was measured at

baseline and post-intervention a month, six months, and 12 months later, using the Subjective

Happiness Scale (SHS). This is a seven point scale, including questions such as ‘In general I

consider myself 1 = not a very happy person to 7 = a very happy person. Results only

revealed effects of increased happiness immediately after the intervention. The authors

suggested that the instructions of the intervention could be made clearer, for greater

endurance of effects. However, the given instructions were more descriptive than those in

similar studies, and the short-lived increase in happiness could be explained by the lack of

control over what participants end up writing (Sexton & Adair, 2018).

Overall, several previous studies have reported the significant success of gratitude

interventions, such as the Three Good Things, and the current study aims to build upon this

line of research. Furthermore, none of the studies found, was based on a single-subject

design. Single-subject designs are considered as a valuable and valid approach for

constructing empirical interventions (Barnett et al., 2004), and the present study aims to

address this gap. The present study, therefore, aims to increase happiness levels through the

implementation of the 3GT intervention, by focussing on what went well in a given day, the

role of the individual in making it happen, and the positive emotions that accompanied each

good thing. Importantly, the goal is also to keep the lack of control in self-administered

interventions, and the subjectiveness of self-report measures, in mind. This study asks the

question ‘Does practising gratitude improve happiness through a PPI?’, and the hypothesis is

that gratitude will improve happiness through the implementation of a PPI.

Method

Design & Participants

The present study will conduct a single-participant pre-test-post-test design where

participants’ happiness scores will be measured prior to the intervention and after the

intervention a week and two weeks later. This single-subject design focusses on a 20-year-

old, female, university student and her in-depth reflection on the positive psychology

intervention employed.

Tools

The Authentic Happiness Inventory (AHI) (Seligman et al., 2005) is a well-known

measure of subjective happiness and it is mainly used in studies on positive psychology

interventions, specifically because of its sensitivity to change in happiness levels (Proyer et

al., 2017). AHI evaluates the changes in happiness that occur as a result of activity-

engagement, positive emotions, the use of strengths, and the idea of contributing to a purpose

outside of oneself (Zabihi et al., 2014). It is, thus, designed to be closely aligned with

Seligman’s (2002) theory of the pleasant, engaged and meaningful life. The questionnaire is

based on a 5-point Likert scale composed of 33 sets of five statements that describe the

individual’s feelings over the previous week. An example includes statements such as “”I am

usually in a bad mood” to “I am usually in an unbelievably great mood” and “My life is a bad

one” to “My life is a wonderful one”. The AHI is also known to have sound psychometric

properties, convergent and discriminant validity, and high correlations of test-retest outcomes

over the time of one week, one month, three months, and six months (Proyer et al., 2017). It

is shown to have high internal consistency (alpha = .93) (Zabihi et al., 2014).

Procedure

The participant completed a pre-test happiness questionnaire, the Authentic Happiness

Inventory, online via Authentic Happiness (https://www.authentichappiness.sas.upenn.edu/).

From that day onward for a week, the participant implemented the Three Good Things

intervention by writing down three things that went well and that the participant was grateful

for that day, what they contributed to each of these positive occurrences, and what emotion

was felt during each of them. On the next Monday, a week later, the participant completed

the AHI again, as the first post-test happiness measure. Once more, the participant applied the

3GT intervention for the second week ending on the last Monday of the study. Finally, the

next day, the participant completed the AHI questionnaire for the last post-test measurement.

Results and discussion

A Positive Psychology Intervention, the Three Good Things intervention, was used to

explore the effects of gratitude on happiness levels, using a pre-test-post-test design. The

Authentic Happiness Inventory questionnaire revealed a pre-test score of 3.71, on a scale of

1-5. The first post-test measure revealed a score of 3.92. This indicates an 0.21 increase in

happiness after one week of the intervention. Finally, the second and last post-test score was

4.08, indicating an increase in happiness of 0.16 after the second week of intervention.

Comparing the pre-test and final post-test scores, happiness levels improved by 0.37.

The present study’s aim was to answer the question of whether practising gratitude

improves happiness through the implementation of a Positive Psychology Intervention. The

findings indicated that the Three Good Things gratitude intervention did improve happiness

levels. There was an increase in happiness levels at the first and second post-test measures

compared to the pre-test score, as well as an increase in happiness between the first and

second post-test measures. Therefore, the hypothesis is supported.

These findings are in line with that of several previous studies (Seligman et al., 2005;

Proyer et al., 2014; Sexton & Adair, 2018; Mongrain and Anselmo-Matthews, 2012) that also

reported increases in happiness at immediate post-test. Seligman et al. (2005). Furthermore,

based on the intervention period of 15 days, the present study’s findings were specifically

consistent with that of Sexton and Adair (2018). However, their sample consisted of

healthcare workers that struggled with burnout and a work-life balance, and therefore their

circumstances were largely different than that of the current study’s participant. It could,

therefore, be suggested that the success of PPIs, such as the 3GT, do not only relate to

circumstances involving severe subjective well-being struggles, but that it can be an effective

strategy for improved well-being in numerous contexts. Furthermore, Sexton and Adair’s

(2018) participants were, similar to the present sample, female. According to Carr (2022),

females tend to experience higher gratitude levels compared to males, and therefore, it can be

suggested that these reported findings are in line with wider research on gender effects,

although direct gender comparisons are needed to confirm this suggestion (Sexton & Adair,

2018).

Furthermore, although Seligman et al. (2005) only implemented the 3GT for one

week, their participants continued the intervention on their own, and this is possibly why

effects were still present a month later. Therefore, as the current findings indicate effects for

two weeks of the intervention, it could be suggested that a longer intervention period is

beneficial for lasting effects on happiness. An intervention period longer that 15 days, can

also possibly aid our understanding of what the ideal implementation time for the 3GT

intervention is and when effects on happiness might start to stagnate, or even decrease.

Lastly, more research should also investigate the specific underpinnings responsible for

increased happiness and well-being (Mongrain and Anselmo-Matthews, 2012).

Before starting the intervention, I tried to keep an open mind about the possible

outcomes. I was not overly optimistic that it would work, as I thought a week-long

intervention would not be enough to produce a significant increase in my level of happiness. I

also consider myself to be someone who tends to be grateful, naturally, and I thought that the

intervention might not make such a large difference, compared to someone for whom

gratitude does not come naturally. Nevertheless, I was eager to find out. The intervention

itself was really easy and quick to implement into my day. Thinking and writing about good

things that happened each day, big or small, came rather naturally, and so did associating a

positive feeling to each of these items. I did, however, had to think a little longer about my

contribution to everything that went well, especially in terms of the small things, such as a

pretty sunset. Near the end of the week, I was quite enjoying the exercise and I even thought

of continuing it in some way even after the intervention was over. Pointing out the highlights

of my day was uplifting and it reminded me to take time to enjoy and appreciate, not only the

bigger social events, but also the smaller things, such as listening to a good podcast or

making a tasty meal. Being intentional with gratitude, gave me a different perspective of, and

brought about so much more meaning to my daily life.

Furthermore, after the first post-test measure, I decided to do the intervention for

another week to see what would happen, although I did not expect any increase in happiness.

On the contrary, I actually thought I would be either just as happy, or less happy than the

previous week. During the second week, although the practice was still quick and easy, it

became a little less enjoyable. However, I was surprised to see that my happiness level

improved even more.

Something that I did note, is that during the first week of my intervention, I was

busier than usual and had more social activities. This definitely contributed to me feeling

more optimistic, happy, and content, and these feelings also flowed into the second week of

the intervention. Perhaps otherwise, the second week of the intervention might not have

brought about such an increase in happiness. Another possible explanation for the unexpected

increases in my happiness, is that, as I have mentioned, I am generally an optimistic and

grateful person. Contrary to what I thought initially, the intervention was not successful

despite of this cognitive bias, but because of it.

Overall, my daily highlights seem to fall into categories, such as spending quality

time with family and feeling loved, reaching out and feeling connected to friends, being

productive with work, taking time to relax and unwind, being encouraged and inspired

through faith-related influences. This seems to corresponds with wider research of

Lyubomirsky et al., (2005, as cited in Andriani & Lukman, 2023). According to them,

individuals who score high on subjective well-being, are more likely to exhibit social,

engaged characteristics, as well as excellent intrapersonal skills. Furthermore, it is suggested

that individuals with high levels of happiness also show increased productivity, prosocial

behaviour, openness to social connections (Armenta et al., 2015, as cited in Andriani &

Lukman, 2023).

These themes also seem to be in line with Seligman’s PERMA model (Carr, 2022).

During each of my daily highlights, felt and wrote down at least one positive emotion, I felt

especially felt engaged when I spent time with friends and family, I definitely built closer

connections and positive relationships with those around me, I found new meaning and

purpose in the small and the bigger daily activities and life in general, and I felt a sense of

accomplishment especially in being productive in my studies.

I specifically focussed on taking in all the good things in each day, and even though

my circumstances during the intervention were not particularly upsetting or stressful, I chose

not to focus on the inconveniences some days may have presented. To be honest, I cannot

even remember what most of these minor disruptions were. I think this further adds to the

essence of what positive psychology is and how, even though we might still have and be

aware of misery, we can choose to shift our perspective towards what we can be thankful for

and that which brings us joy and fulfilment.

I also definitely believe that as I practiced gratitude, I became more aware of daily

activities and joys that I, perhaps, normally would forget to be grateful for. However, I did

not measure my gratitude levels and I think it would have been interesting to compare such

scores with my happiness levels. This way I would have been able to see whether the

intervention indeed improved my level of gratitude. I would also be able to see whether there

is a connection between gratitude, itself, and happiness, and not just the effect of practicing

gratitude on my levels of happiness. Completing a gratitude questionnaire alongside the

implementation of a gratitude intervention, is therefore another suggestion for future research

on PPIs. Further, an intervention period longer that 15 days, can possibly aid our

understanding of what the ideal implementation time for the 3GT intervention is and when

effects on happiness might start to stagnate, or even decrease. Lastly, more research should

also investigate the specific underpinnings responsible for increased happiness and well-

being (Mongrain and Anselmo-Matthews, 2012).

Conclusion

The study aimed to explore the effects of practicing gratitude on happiness levels,

through a Positive Psychology intervention. Findings indicated that the practice of gratitude

did lead to an increase in happiness. These findings contribute to the success of PPIs,

especially that of the Three Good Things gratitude intervention. It shows that a simple daily

exercise, highlighting the positive moments that otherwise might have been left unnoticed,

can change one’s perspective to be more thankful and lead to emotions that curate happiness.

Limitations of the study include the subjectivity of individual experiences and the self-report

measures used, and the fact that the short implementation period does not account for long-

term effects of the intervention. Together with measuring gratitude alongside happiness

levels, future research should, therefore, extend the intervention period, and investigate the

particular components that support improvement in happiness.

References

Andriani, F., & Lukman. (2023). The Three Good Things intervention to improve subjective

well-being in students. Jurnal Intervensi Psikologi, 15(1).

https://doi.org/10.20885/intervensipsikologi.vol15.iss1.art4

Barnett, D. W., Daly, E. J., Jones, K. M., & Lentz, F. E. (2004) Response to intervention:

Empirically based special service decisions from single-case designs of increasing and

decreasing intensity. The Journal of Special Education, 38(2), 66-79.

Bolier, L., Haverman, M., Westerhof, G. J., Riper, H., Smit, F., & Bohlmeijer, E. (2013).

Positive psychology interventions: A meta-analysis of randomized controlled studies.

BMC Public Health, 13(119). https://doi.org/10.1186/1471-2458-13-119

Carr, A. (2022). Positive psychology (3rd ed.). Taylor and Francis.

Cunha, L. F., Pellanda, L. C., & Reppold, C. T. (2019). Positive psychology and gratitude

interventions: A randomized clinical trial. Frontiers in Psychology, 10.

https://doi.org/10.3389/fpsyg.2019.00584

Killen, A., & Macaskill, A. (2015). Using a gratitude intervention to enhance well-being in

older adults. Journal of Happiness Studies, 16, 947-964.

Kristjansson, K. (2010). Positive psychology, happiness, and virtue: The troublesome

conceptual issues. Review of General psychology, 14(4), 296-310.

https://doi.org/10.1037/a0020781

McCabe, K., Bray, M. A., Kehle, T. J., Theodore, L. A., & Gelbar, N. W. (2011). Promoting

happiness and life satisfaction in school children. Canadian Journal of School

Psychology, 26(3), 177-192. https://doi.org/10.1177/0829573511419089

Mongrain, M., & Anselmo-Matthews. (2012). Do positive psychology exercises work? A

replication of Seligman et al. (2005). Journal of Clinical Psychology, 68(4) 373-486.

https://doi.org/10.1002/jclp.21839

Proyer, R. T., Gander, F., Wellenzohn, S., & Ruch, W. (2014). Positive psychology

interventions in people aged 50-79 years: Long-term effects of placebo-controlled

online interventions on well-being and depression. Aging Mental Health, 18(8), 997-

1005. https://doi.org/10.1080/13607863.2014.899978

Proyer, R. T., Gander, F., Wellenzohn, S., & Ruch, W. (2017). Authentic Happiness

Inventory revised: Addressing ist psychometric properties, validity, and role in

intervention studies. Journal of Well-Being Assessment, 1, 77-96.

https://doi.org/10.1007/s41543-018-0006-0

Rash, J. A., Matsuba, M. K., & Prkachin, K. M. (2011). Gratitude and well-being: Who

benefits the most from a gratitude intervention? Applied Psychology: Health and

Well-Being, 3(3), 3-369.

Schiffrin, H. H., & Nelson, S. K. (2010). Stressed and happy? Investigating the relationship

between happiness and perceived stress. Journal of Happiness Studies, 11, 33-39.

https://doi.org/10.1007/s10902-008-9104-7

Seligman, M. E. P. (2010). Flourish: Positive psychology and positive interventions. The

Tanner Lectures on Human Values

Seligman, M. E. P., Ernst, R. M., Gillham, J., Reivich, K., & Linkins, M. (2009). Positive

education: Positive psychology and classroom interventions. Oxford Review of

Education, 35(3), 293-311. https://doi.org/10.1080/03054980902934563

Seligman, M. E. P., Steen, T., A., Park, N., & Peterson, C. (2005). Positive Psychology

Progress: Empirical Validation of Interventions. American Psychologist, 60(5), 410–

421. https://doi.org/10.1037/0003-066X.60.5.410

Sexton, J. B., & Adair, K. C. (2018). Forty-five good things: a prospective pilot study of the

Three Good Things well-being intervention in the USA for healthcare worker

emotional exhaustion, depression, work-life balance and happiness. BMJ Open, 9(3).

http://dx.doi.org/10.1136/bmjopen-2018-022695

Sin, N. L., & Lyubomirsky, S. (2009). Enhancing well-being and alleviating depressive

symptoms with positive psychology interventions: A practice-friendly meta-analysis.

Journal of Clinical Psychology, 65(5), 467-487. https://doi.org/10.1002/jclp.20593

Zabihi, R., Ketabi, S., Tavakoli, M., & Ghadiri, M. (2014). Examining the internal

consistency, reliability and construct validity of the Authentic Happiness Inventory

(AHI) among Iranian EFL learners. Current Psychology, 33, 317-392.

https://doi.org/10.1007/s12144-014-9217-6