Enhancing Life Satisfaction through Eudaimonic, Hedonic, and Combined Interventions: New Training Approaches Relevant to Theory and Practice

Eudaimonia and hedonia have been discussed as two routes to well-being since ancient times (Keyes & Annas, 2009). They have sometimes been seen as opposing and, at others, as mutually complementary. Philosophers have discussed the two aspects in the context of a happy or fulfilled life, and competing positions exist that were meant to be normative guidelines on how to live. Aristoppus is often cited as an advocate of hedonia, whereas Aristoteles is known to have emphasized eudaimonia (Huta & Ryan, 2010). Building on various definitions of hedonia and eudaimonia (see Huta & Waterman, 2014, for an overview), Huta (2022) has summarized the main characteristics as follows: “hedonia includes two main components: pleasure/enjoyment/fun and absence of pain/discomfort” (p. 511), while “eudaimonia often includes authenticity/autonomy, excellence/virtue, growth/self-actualization and meaning/contribution” (pp. 511–512). In our research, we rely entirely on Huta’s perspective and define a person’s behaviors/ attitudes as hedonic if they target pleasure or absence of discomfort, and we define them as eudaimonic if they target the proposed eudaimonic characteristics (e.g., meaning, growth; s. above).

Several studies have analyzed the relationship between hedonia and eudaimonia using correlational analysis (e.g., Mason, 2019; Turban & Yan, 2016). This line of research has shown that the average correlations between eudaimonia and hedonia indicators vary between r = −.3 and 0.8 (Huta & Waterman, 2014); in other words, they range from positive to negative. Both components have been shown to be relevant for well-being and other outcomes in intervention studies that manipulated either hedonia or eudaimonia (Cardona et al., 2020; George et al., 2021). Since such studies allow for causal interpretations, they are of particular importance. Henderson et al. (2013) concluded (p. 334) “Future research should therefore utilise manipulation designs, such as hedonic and eudaimonic intervention studies.”

In contrast to the normative ancient positions in philosophy, psychologists conceptualize hedonia and eudaimonia as distinct, though not fully incompatible. The combination is of special interest because the idea is that the combination of eudaimonia and hedonia could have special benefits, or, as Huta and Ryan put it, “(…) hedonia and eudaimonia occupy both overlapping and distinct niches within a complete picture of well-being, and their combination may be associated with the greatest well-being” (2010, p. 734). This leads us to describe our main assumptions, i.e., full-life effectivity and full-life superiority.

Full-life effectivity. It could be argued that not only do the two components of hedonia and eudaimonia play a role in our lives, but that following both may also be beneficial to our life satisfaction. We refer to this assumption as full-life effectivity. Note that this assumption is not self-evident, because studies also exist which show that hedonia and eudaimonia could be incompatible under some conditions (Huta & Ryan, 2010).

Full-life superiority. We assume that the combination of hedonia and eudaimonia is even more effective than the single components (Huta & Ryan, 2010). Applying combined hedonia and eudaimonia interventions might then lead to higher life satisfaction than only targeting the single components of either hedonia or eudaimonia.

Huta and Waterman (2014) and Huta (2022) differentiate between different levels of measurement of eudaimonia and hedonia. These levels include specific orientations (motives, goals), behaviors (actions), experiences (affects, feelings), and functions (abilities, strengths). Considering these levels may help to explain some of the mixed empirical results. Eudaimonia and hedonia may be unrelated or even positively related when considered as trait-like characteristics, although eudaimonic and hedonic experiences may be very different and even negatively related at a given moment. We consider hedonia and eudaimonia in this study as behaviors and attitudes.

Huta and Ryan (2010) conducted an intervention study that is of particular importance for the topic because it focuses on the relationship between hedonia and eudaimonia. It does, however, have some shortcomings. Firstly, Huta and Ryan (2010) only examined separate interventions for eudaimonia and hedonia, not a combination of the two, although the eudaimonia-hedonia interplay was a major theme for them. Secondly, the study did not contain a control group. Thirdly, the study dealt with the motivation for hedonia and eudaimonia rather than the actual behavior (cf. Henderson et al., 2013). Two other studies are worth mentioning as they implemented specific combinations of intervention components related to eudaimonia and hedonia: Giannopoulos and Vella-Brodrick (2011) and Gander et al. (2016). A fairly simple intervention was used in both studies, namely a variation of the “Three Good Things” exercise, which was applied to the hedonia and eudaimonia components. Regarding pleasurable things, for example, participants were asked: “Remember three things you have experienced today that were related to fun, amusement, joy, or pleasure…”. Regarding meaning, they were asked: “Remember three things you have experienced today that were related to meaning…”.

Giannopoulos and Vella-Brodrick (2011) built on the OTH-Model (Orientations to Happiness Model: pleasure, meaning, and engagement) and adapted the “Three Good Things” exercise to three pleasurable things, three meaningful things, and three engaging things. The variant of a combined task consisted of coming up with one pleasant, one meaningful, and one engaging thing. Gander et al. (2016) varied their instructions to distinguish between the separate and combined activation of the PERMA facets (pleasure, engagement, positive relationships, meaning, and accomplishment). In the combined version, participants were asked to “remember one thing from each of the following topics pleasure, engagement, meaning, positive relationships, and accomplishment” (Gander et al., 2016, p. 3). It is crucial to note that these instructions led to differences in intensity. We introduce the aspect of intensity because it could be an important but formerly neglected aspect of this kind of training. If you are asked, for example, to state one pleasurable thing or to list three pleasurable things, this implies different levels of intensity of dealing with pleasure. And the more intensively you deal with a topic, the more impact you can achieve. We define an intensity of one unit (1) if there is one question for that topic. In the study of Giannopoulos and Vella-Brodrick (2011), each single intervention asked for three things and the combined intervention also asked for three things. That means the intensity of the combined intervention (3) is equal to the intensity of each single intervention (3). At the same time, this also means that a component such as pleasure is only asked for once in the combined intervention, leading it to be captured with an intensity of only 1, compared to 3 in the single intervention. The question is whether the combined intervention still works even if each component is trained with lower intensity (1/3) than in the single intervention.

When it comes to conclusions regarding the assumptions of full-life effectivity and full-life superiority, the results of Giannopoulos and Vella-Brodrick (2011) and Gander et al. (2016) have demonstrated that combinations of hedonia and eudaimonia are effective (full-life effectivity), but that the effects of the combinations did not exceed the single-component interventions (no full-life superiority).

Summarizing the knowledge about combined interventions for hedonia and eudaimonia, we conclude that they are worth exploring further, and a combined approach could be effective and even more so than focusing on single components. We try to solve the problem of comparable intensity in our second study by training each component of the combination with the same intensity as in the single intervention.

Analyzing ways to increase well-being is sometimes hindered by conceptual and measurement problems. The differentiation between well-being and its predictors is inconsistent in well-being research. Consider, for example, eudaimonic well-being, measured with the QEWB (Questionnaire for Eudaimonic Well-being, Waterman et al., 2010). This questionnaire contains items such as “I believe it is important to know how what I’m doing fits with purposes worth pursuing.” Does this item really reflect (eudaimonic) well-being? The focus of the item is more on a belief that could lead to a behavior that, in turn, promotes well-being.

A distinction must be made between attitude, behavior, and well-being to provide conceptual clarity. Huta and Ryan (2010), for instance, have responded to the issue of conceptual clarity by using the terms “eudaimonia” and “hedonia” in their instrument HEMA (Hedonic and Eudaimonic Motives for Activities) to represent motives for acting, which they see as predictors of well-being outcomes. We fully agree with their view that it is necessary to distinguish between predictors of well-being and well-being as an outcome. This also builds a main conceptual grounding for the present research. We argue for a distinction between pathways to well-being and well-being itself. This distinction is conceptual, but also has implications for measurement and research designs.

The art-of-living concept was introduced into the social sciences by Veenhoven (2003). He pointed to the aforementioned necessity to differentiate between ways to well-being and well-being as a result. In our view, we define any behavior or attitude is a pathway to well-being if a positive change in that attitude/behavior actually leads to an increase in well-being.

In previous meta-analyses, the duration of positive psychological interventions (Sin & Lyubomirsky, 2009) is often more than eight weeks. Therefore, we wanted to show that a shorter intervention (≤ 4 weeks) can also be effective. Another feature of our intervention is that it takes place online. We chose an online rather than an offline intervention because digital interventions are more flexible to use (Richmond et al., 2017). Furthermore, we applied a suite of highly varied exercises and allowed for different kinds of choice of exercises to avoid the treadmill effects of adaptation (Sheldon & Lyubomirsky, 2012).

We expect our training interventions to increase art-of-living strategies as well as well-being. As there are different ways to conceptualize well-being (e.g., affective vs. cognitive well-being, domain-specific vs. general well-being; see Diener et al., 2018), it is necessary to decide on a specific indicator to focus on. A frequently used concept is life satisfaction (Diener et al., 1985). We decided to use it in our study as well. There are good reasons to do that. Huta (2022), for instance, argues that life satisfaction is a reasonable proxy for the single factor for hedonic and eudaimonic well-being.

We lay out our hypotheses in the following. They refer to two outcomes: the art-of-living and life satisfaction, the former being both a direct outcome and a mediator of the latter.

In a first step, we compared the three sub-samples in terms of pre-post changes for the art-of-living and life satisfaction. No significant differences were found. We, therefore, carried out the following analyses using data from the overall sample.

We found that hedonia training is effective and provides stable results for the art-of-living and life satisfaction. In the same vein, the combined training turned out to be effective, with maintenance of its effects on the art-of living and life satisfaction from the posttest to follow-up measurement. Thus, the full-life effectivity is confirmed. As proposed, significant intervention effects of hedonia and combined training on life satisfaction were mediated by the art-of-living.

In addition to these significant findings, which were in line with our hypotheses, some other hypotheses were not supported. Eudaimonia training led to an enhanced art-of-living but left life satisfaction unaffected. This result was unexpected, as previous research has repeatedly shown that the art-of-living is positively related to well-being (Schmitz et al., 2022). Another unexpected finding was that the combined training did not show consistently stronger effects than the single-component training (i.e., the full-life superiority was not confirmed). A possible explanation for why the combined training did not show higher effectiveness than the two single-component interventions could be its intensity. In fact, it was as intensive as that of the two single-component interventions and, therefore, the hedonia and eudaimonia parts in the combined group are trained with half the intensity of the hedonia, respectively, the eudaimonia group. Perhaps this has reduced the effects of the combined training. This reasoning is in line with Lyubomirsky and Layous (2013), who have argued that the dosage/intensity of a well-being intervention is a crucial parameter for its effectiveness.

The combination of the three sub-studies within Study 1 has advantages and disadvantages. The chosen procedure led to a higher number of cases and, thus, to more reliable statistical analyses. In addition, the combination strengthens external validity, as the results are obtained through interventions that differ in finer details but are not limited to a specific implementation of the training. Still, merging is a limitation, as we cannot know whether certain variants were particularly effective. Note, however, that there were no differences between the subsamples regarding changes in the art-of-living and life satisfaction.

Study 2 differs from Study 1 as it includes only two intervention groups: a eudaimonia and a combined group. Nonetheless, a waiting list control group was again included. Participants were randomly assigned to one of the three groups. The design is shown in Fig. 1.

The eudaimonia intervention had positive effects on the art-of-living and life satisfaction in Study 2. These effects were stable from posttest to follow-up. Furthermore, we demonstrated that the combined training was effective regarding the art-of-living and life satisfaction, and that these effects were stable from posttest to follow-up (full-life effectivity). We had predicted that combined training would be superior to single-component training. Again (similar to Study 1), this could not be demonstrated (no full-life superiority). We had expected that the more intense training would make the combined training more effective than the less intense single-component training. Lyubomirsky and Layous (2013) have argued that there is a quadratic nonlinear relationship between intensity/dosage and well-being enhancement. However, it is not yet known what intensity of training is required to reach a peak of well-being. Therefore, it may be that the intensity of Study 1 had already led to a maximal effect and further extension of the intensity in Study 2 did not increase efficacy.

Similar to any study, our research is not without limitations. Firstly, we did not assess how accurately the exercises were completed. It would be useful to know which exercises were applied, for how long and how participants evaluated them. Such data could be used in future research to analyze relationships between specific exercises and intervention effectiveness. Secondly, the design in Study 2 was somewhat limited, as it did not include a hedonia group. We applied this design to save resources. Thirdly, we used the SWLS as a well-being measure. In doing so, we relied on the findings of Huta and Ryan (2010) and Huta (2022), which differ from those of other authors who have interpreted life satisfaction as a pure indicator of hedonic well-being. By contrast, Huta (2022) has shown that life satisfaction, as measured by the SWLS, is an indicator of hedonic and eudaimonic well-being. Huta and Ryan noted that “there was fair evidence that life satisfaction related to both hedonia and eudaimonia…” (2010, p. 758), and in Huta it is said that “life satisfaction did serve as reasonable proxy of the single factor,…” (2022, p. 534). However, one could argue that life satisfaction is more closely related to hedonic well-being. Therefore, our results should be interpreted with caution and further evidence is needed that they are transferable to other indicators of well-being, for example, the PANAS (Positive and Negative Affect Schedule, Watson et al., 1988) or the QEWB (Questionnaire for Eudaimonic Well-being, Waterman et al., 2010). Note that Peterson et al. (2005) also used life satisfaction as a criterion in their correlational study of the full-life. Given this limitation regarding the well-being outcome used in the present studies, we propose to conclude that the training effects on well-being are specifically related to “life satisfaction.” Fourthly, the time span for the follow-up is crucial for questions regarding the stability of the intervention effects. The results regarding stability can only be interpreted regarding the time-span selected for the present studies, i.e., two to three weeks. Fifthly, the sample is quite homogenous. Whether our results can be generalized when more heterogeneous samples are examined remains to be seen in future research. Sixthly, interventions were presented online, which may result in limited participation for some people. Even though it can be assumed that access to computers and the internet is hardly restricted nowadays and that the practical advantages of online training are high, it might make sense to combine online training with offline sessions to maximize effectiveness. An additional training feature that future studies might implement to increase effectiveness involves continued monitoring by the trainees themselves. In fact, Schmitz and Perels (2011) have shown that training effects can be improved if participants monitor their behavior by completing standardized diaries.

One important result was that we could not demonstrate full-life superiority. But it may be that other ways to combine hedonia and eudaimonia might be more effective. The synergy between the two components could be promoted by applying Rusk et al.’s (2018) Synergetic Change Model. This model describes ways that components from different contexts interact and generate spillover and synergy effects. Spillover can occur through common factor effects, such as expectancy effects. An expectancy to master a body exercise, for instance, may transfer to the expectancy to master tasks involving social interactions. Synergy effects can take place in upward spirals, for example, when gratitude initiates positive social interaction, which, in turn, enhances gratitude, and so on. Applying insight from this model to our training procedures could enhance their synergy. Savoring exercises, for example, in the hedonic training could promote mindfulness, which, in turn, could lead to behaviors such as purposeful work or religious activity being carried out more mindfully. Future studies should test such applications of the Synergetic Change Model.

Though the present studies had some limitations, they also have important strengths on the following levels: theoretical/conceptional, methodological, and practical. On a theoretical/conceptional level, we were interested in the enhancement of life satisfaction. We considered hedonia and eudaimonia strategies with a special interest in the relationship between them. Unlike most previous studies, we approached this relationship by interventions regarding its combination. We tested for both the full-life effectivity and full-life superiority. The differentiation between well-being and ways to well-being is important for measuring the effects of our courses of training. In considering the different levels of eudaimonia and hedonia, we applied behavioral interventions. Following the model of Lyubomirsky and Layous (2013), we took the intensity/dosage of the interventions into account. In contrast to previous combined approaches (Giannopoulos & Vella-Brodrick, 2011; Gander et al., 2016), we restricted our combined intervention to hedonia and eudaimonia to actually draw conclusions focusing on exactly these two components and their combination. Methodologically, we applied randomized control group designs with follow-ups. We partially replicated our findings in a second study and applied a mediation model. Practical aspects are also worth mentioning. The study is online, of short duration, and includes a variety of exercises which are more complex and, therefore, more interesting than in previous studies.

In summary, our research provides evidence of full-life effectivity, with eudaimonia and hedonia not being enemies at all. Both contribute to a person’s individual art-of-living, which, in turn, enhances and sustains life satisfaction. Uncovering the interplay between eudaimonia and hedonia is a fascinating research endeavor, and intervention approaches can offer a lot to this perspective in terms of both refining theory and providing practical guidance.