“The unexamined life is not worth living.” —Socrates

The pursuit of a meaningful life is a fundamental human goal that transcends cultural boundaries (King & Hicks, 2021). In Western thinking, self-knowledge has long been recognized as a fundamental pillar for living a fulfilling life and is closely linked to the experience of meaning (Deci & Ryan, 2000; Hong et al., 2022; Shin et al., 2016). However, the role of self in fostering meaning in life has received limited empirical attention within collectivistic cultural contexts, where the emphasis on individual self is less pronounced, and the specific mechanisms through which self-concept clarity influences meaning in life remain largely unexplored.

In contemporary China, many young people find themselves adrift, lacking a clear sense of identity and purpose in life, leading to a pervasive sense of meaninglessness. This phenomenon has even been encapsulated by the emergence of a popular term, "hollow heart disease" (Xu, 2016). Within collectivistic cultures like China, individuals are seldom encouraged to develop a deep understanding of themselves and to explore their own aspirations and desires (Kitayama & Salvador, 2023; Markus & Kitayama, 1991). Instead, there is often a tendency to conform to the opinions and expectations of the majority (Bond & Smith, 1996). The lack of centrality of self and thereof low self-concept clarity could contribute to the prevailing sense of meaninglessness experienced by Chinese youths.

This study aims at providing further evidence regarding the impact of self-concept clarity on meaning in life and explore the underlying mechanism (i.e., the mediating role of coherence, purpose, and significance). By conducting research within the context of daily life, we aimed to simultaneously reveal the between-person effects, within-person effects, and temporal effects. Utilizing a sample from China, we tested whether the theoretical significance of self-concept clarity observed and articulated in Western cultures also holds within a collectivistic culture. Meanwhile, we examined the moderating role of independent self-construal, which serves as an individual-level counterpart to cultural individualism-collectivism. This study endeavored to deepen the current understanding of the relationship between self-concept clarity and meaning in life in a different cultural context and provide insights into promoting a meaningful life in China and beyond.

1 Knowing Oneself: Self-concept Clarity and Meaning in Life

Meaning in life is a key component of eudaimonic well-being (Diener et al., 2018; Ryff, 1989), contributing to positive development and better psychical and mental health (Bailey & Phillips, 2016; Boyle et al., 2010). While research on hedonic well-being, such as life satisfaction and positive affect, has received considerable attention, the investigation on meaning in life, has emerged more recently (Baumeister et al., 2013; Costin & Vignoles, 2020; King & Hicks, 2021; Steger et al., 2006).

Within the realm of meaning in life, recent research suggests that there are three precursors of meaning: coherence, purpose, and significance (Costin & Vignoles, 2020; George & Park, 2016; King & Hicks, 2021; Martela & Steger, 2016). Coherence involves perceiving one’s life as understandable and interconnected, purpose reflects the feeling that one's action is guided toward their personally valued goals, and significance pertains to the feeling that one’s life holds importance and impact across space and time (Costin & Vignoles, 2020; George & Park, 2016; King & Hicks, 2021; Martela & Steger, 2016). While social connections have been acknowledged as significant sources of meaning in life (Baumeister & Leary, 1995; Hicks & King, 2009; Lambert et al., 2013), the self also plays a crucial role in this regard (King & Hicks, 2021). Both self and the existential contemplation of meaning in life are essential aspects of human essence (Gregg & Sedikides, 2017). Notably, the intertwining of self and meaning in life is also reflected by a research showing that self contributes exclusively to meaning but not to happiness (Baumeister et al., 2013).

Self-concept clarity is an essential foundation for individuals to live a meaningful life. Self-concept clarity, which refers to the extent to which beliefs about self (e.g., personality traits, values, and beliefs) are clearly and confidently defined, internally consistent, and stable (Campbell et al., 1996), is the most fundamental aspect of cognitive self (Jiang et al., 2020; Shin et al., 2016). According to the self-determination theory, people possess an innate psychological need for autonomy and self-actualization, motivated not solely by external influences but also by their own values and identities (Deci & Ryan, 2000). Consequently, a clear understanding of oneself, including personal values and goals, serves as the foundation for exercising autonomy and self-actualization, thereby contributing to a heightened sense of meaning in life (Martela et al., 2018). This perspective echoes the insights of Western existential thinkers spanning centuries, who emphasized the significance of individual agency, self-reflection, and personal choice in living a meaningful life, including Kierkegaard, James, and Rogers, or even longer ago (e.g., the proverb “know theyself” is inscribed in the Temple of Apollo at Delphi in Ancient Greek) (Kernis & Goldman, 2006; Schlegel et al., 2011). Additionally, Erikson's (1956) concept of identity achievement and Marcia's (1966) theory further underscore the importance of developing an internally defined sense of identity in fostering meaning and purpose.

Empirical studies have provided support for the relationship between self-concept clarity and meaning in life. For instance, research conducted in Poland demonstrated that self-concept clarity positively predicted purpose in life through the mediation of religious orientation (Błażek & Besta, 2012). Another study found that self-concept clarity enhanced work motivation by promoting perceived work meaningfulness (Oh & Roh, 2019). Furthermore, self-concept clarity was found to drive learning engagement through its influence on the sense of life meaning (Liu et al., 2023). In nursing students, self-concept clarity exhibited a negative association with depression, partially mediated by meaning in life (Hong et al., 2022). Longitudinal research in the United States revealed that an increase in self-concept clarity corresponded to an increase in meaning in life (Shin et al., 2016). However, a study yielded inconsistent findings, as the accessibility of the actual self-concept, which reflected self-concept clarity, failed to predict meaning in life (Schlegel et al., 2009).

Despite these valuable contributions, a comprehensive understanding of the mechanism between self-concept clarity and meaning in life is yet to be fully explored. Previous studies have not extensively examined this relationship from a multidimensional perspective of meaning in life (George & Park, 2016; King & Hicks, 2021; King et al., 2006). Such an approach seeks to investigate the possibility that self-concept clarity is crucial to the sense of meaning by promoting coherence, purpose, and significance in comprehending one's life experiences.

2 Self-concept Clarity and Three Precursors of Meaning: Coherence, Purpose, and Significance

The literature on self and identity has consistently highlighted the role of self-knowledge in making sense of life (Gregg & Sedikides, 2017). Theories addressing the concept of meaning in life have also suggested that individuals understand and interpret their lives based on their connection with their own selves (King & Hicks, 2021). Additionally, Heine et al. (2006) proposed that a crucial aspect of meaning lies in the relationality between individuals and the events happening around them, as this connection shapes their understanding of the world. However, despite these insights, empirical studies have yet to confirm the association between self-concept clarity and coherence.

Self-concept clarity plays a vital role in the establishment of one's life purpose. Previous research has demonstrated that self-concept clarity can predict an individual's sense of purpose (Błażek & Besta, 2012). A clear and coherent self-narrative serving as an adaptive mechanism for finding meaning (Adler et al., 2016; McAdams & Olson, 2010).

While significance has historically been overlooked by theorists, recent findings have identified it as the most important precursor to meaning among the three factors (Costin & Vignoles, 2020; Martela & Steger, 2022). Although without previous empirical evidence linking self-concept clarity and significance, it is still plausible to hypothesize that association by awing on indirect evidence of the positive association between self-concept clarity and self-esteem (Campbell et al., 1996; Usborne & Taylor, 2010). Individuals with high self-esteem tend to perceive themselves as valuable and worthy (Pyszczynski et al., 2004).

3 Present Study: Using the Daily Dairy Method

To date, there is a lack of studies investigating the relationship between self-concept clarity and meaning in life within the context of everyday life, which would offer higher ecological validity. Daily diary studies, which assess variables of interest frequently and at short intervals, offer a means to reduce recall bias and provide a more accurate assessment compared to cross-sectional surveys (Csikszentmihalyi & Larson, 1987). Previous studies examining the relationship between self-concept clarity and meaning in life have primarily utilized a cross-sectional design, focusing solely on between-person relationships and neglecting the within-person dynamics between self-concept clarity and the sense of meaning.

However, it is crucial to recognize that the between-person relationship does not necessarily mirror the within-person relationship, and assuming their equivalence can lead to an "ecological fallacy" (Sedgwick, 2015). Previous daily diary studies have indicated that self-concept clarity can fluctuate within an individual based on their daily life experiences (Emery et al., 2023; Nezlek & Plesko, 2001), and there is also meaningful within-person variance in the daily sense of meaning (Emery et al., 2023; Kashdan et al., 2018; Martela et al., 2018; Nezlek & Plesko, 2001). It remains unknown whether, on days when individuals experience higher self-concept clarity than usual, they also experience a higher sense of meaning than usual. Moreover, tracking the day-to-day fluctuations in meaning can help identify important factors that contribute to the sense of meaning in life through lagged relationships (Killingsworth & Gilbert, 2010). This approach allows us to explore whether the three precursors of meaning (i.e., coherence, purpose, and significance) from previous days predict meaning in the following days, as theorized (Costin & Vignoles, 2020; King & Hicks, 2021; Martela & Steger, 2022), and whether self-concept clarity from previous days predicts meaning and its three precursors.

In this study, we hypothesized that, for a given individual, on days when they perceive clearer self-concept than usual, they will also perceive that day as more coherent, experience a stronger sense of purpose in life, and consider their life as more significant, leading to a higher sense of meaning than usual (i.e., within-person relationship). However, the between-person relationship may be weaker, as different individuals may perceive the sense of meaning differently and derive the three precursors (i.e., coherence, purpose, and significance) from various sources apart from the self. For example, some individuals may find a life driven by purposes, tasks, or missions to be meaningful, while others may not, but perceiving such a life as lacking meaning if they prefer a less goal-oriented and free-spirited life. Furthermore, for some individuals, self-concept clarity may not be directly related to their daily sense of purpose, as their life purpose may stem from the needs of significant others and social roles rather than from their own identity.

Although there has been little prior research investigating these relationships in a daily dairy setting, we built upon on the existing literature and hypothesized the associations between self-concept clarity, three precursors, and sense of meaning at both between-person and within-person levels as below:

3.1 Between-person effects

Hypothesis 1a (H1a): trait self-concept clarity positively predicts daily meaning.

Hypothesis 2a (H2a): daily coherence, purpose, and significance mediated the relationship between trait self-concept clarity and daily meaning.

3.2 Within-person effects

Hypothesis 1b (H1b): daily self-concept clarity positively predicts daily meaning.

Hypothesis 2b (H2b): daily coherence, purpose, and significance mediated the relationship between daily self-concept clarity and daily meaning (Figs. 1, 2).

Fig. 1
figure 1

Between-person conceptual model

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Fig. 2
figure 2

Within-person conceptual model

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Regarding the temporal relationships, we proposed reciprocal relationships between daily self-concept clarity and meaning in life (Hypothesis 3). Clearer self-knowledge may serve as an internal guide for leading a meaningful life. Simultaneously, perceiving life as meaningful is likely to enhance psychological functions that facilitate better self-exploration and self-understanding (Shin et al., 2016). The same assumptions applied for self-concept clarity and three precursors of meaning. A recent longitudinal study utilizing a cross-lagged panel model found a reciprocal relationship between self-concept clarity and subjective well-being in a Chinese sample, although the temporal relationships were not robust when employing a random-intercept cross-lagged panel model (Xiang et al., 2023).

4 The Moderating Role of Independent Self-construal in a Collectivistic Culture

Theories on the relationship between self-concept clarity and meaning in life have primarily been developed based on the thinking of Western individualistic societies (Deci & Ryan, 2000; Kernis & Goldman, 2006). Previous studies examining self-concept clarity and meaning in life have predominantly focused on samples from individualistic cultures, such as the United States (Błażek & Besta, 2012; Shin et al., 2016). However, the effect of self-concept clarity on meaning in life may not be universal across different cultures due to variation in self-construal, which refers to the way individuals perceive and interpret themselves in relation to others and the broader social context (Markus & Kitayama, 1991). In individualistic societies, where the self is more salient, people tend to have an independent self-construal that emphasizes the importance of being unique and acting autonomously as an individual (Markus & Kitayama, 1991; Singelis, 1994). In contrast, collectivist societies prioritize social integration, even at the expense of one's self, and have a weaker distinction between the self and others (Markus & Kitayama, 1991; Singelis, 1994).

Collectivistic cultures may derive sense of meaning from different sources (Oishi et al., 2013). Those with a high interdependent self-construal in collectivist cultures may place less emphasis on the personal self, which includes personal identities like personality and strengths, and instead focus more on the collective self, which incorporates social roles (Oishi et al., 2007). Previous research has shown that individuals from collectivistic cultures, such as Japan, tend to have lower self-concept clarity compared to those from individualistic cultures like Canada (Campbell et al., 1996). In collectivistic cultures, people may prioritize social consistency over self-consistency, which implies lower stability of self-concept and higher susceptibility to others' influence (Hoshino‐Browne, 2012; Muthukrishna & Schaller, 2020). Therefore, the association between self-concept clarity and meaning in life in a collectivistic culture may not be as strong as shown by previous studies conducted in individualistic cultures (Błażek & Besta, 2012; Schlegel et al., 2009; Shin et al., 2016). For example, the association between self-concept clarity and self-esteem was weaker for Japanese individuals compared to Canadians (Campbell et al., 1996).

Moreover, within the collectivistic culture, self-construal may moderate the relationship between self-concept clarity and meaning in life as well. For individuals with a low independent self-construal, the effect of self-concept clarity on well-being might be weaker since the self is not a focal domain for them. On the other hand, individuals with a high independent self-construal may be more likely to derive meaning from their self-identity. A relevant study showed that the relationship between self-concept consistency and well-being was weaker for individuals with a highly relational self-construal (Cross et al., 2003).

This research aimed to explore whether self-concept clarity contributes to meaning in life within a collectivistic cultural context, thereby examining the universality versus cultural specificity of the effect. Additionally, we examined whether independent self-construal moderates the effect of self-concept clarity on meaning in life:

Hypothesis 4a (H4a): Effect of trait self-concept clarity on daily meaning (and its three precursors) is stronger for individuals with a high (vs. low) independent self-construal.

Hypothesis 4b (H4b): Effect of daily self-concept clarity on daily meaning (and its three precursors) is stronger for individuals with a high (vs. low) independent self-construal.

5 Methods

5.1 Participants and Procedure

A total of 103 college students from Fudan University in Shanghai, China, voluntarily participated in our study. They completed an intake questionnaire that included trait-level measures and demographic information on a Chinese survey platform called “Wenjuanxin”. Over the following 10 consecutive days, participants received online daily dairy surveys via message and answered questions about their daily experiences. The daily dairy surveys were accessible from 6 p.m. to 6 a.m. on the next day (Martela et al., 2018). Those who had never completed a daily survey or completed only one daily survey were excluded from the analysis due to insufficient daily-level information, resulting in a final sample of 83 participants (59 women, Mage = 22.36, SD = 2.92). Participants submitted a total of 732 daily dairies, with an average of 8.82 daily dairies per participant during the daily dairy session. The study was approved by the research ethical committee in Fudan University.

5.2 Measures

All measures were on a 7-point Likert scale (1 = strongly disagree, 7 = strongly agree) unless otherwise specified. The Chinese versions of the scales were obtained through a translation and back-translation procedure by four postgraduate students majoring in psychology.

5.2.1 Trait-level Measures

Trait self-concept clarity was measured using the 12-item Self-Concept Clarity Scale (SCCS) (Campbell et al., 1996). Participants responded to items such as "In general, I have a clear sense of who I am and what I am”.Footnote 1 The Cronbach’s alpha for this scale was 0.88.

Independent and interdependent self-construals were measured using the 12-item scales developed by Singelis (1994) for each construct. For independent self-construal, participants responded to items such as “I am comfortable for being singled out for praise and rewards”, while for interdependent self-construal, participants responded to items such as “It is important for me to maintain harmony within my group”.Footnote 2 The Cronbach’s alphas were 0.71 for independent self-construal and 0.81 for interdependent self-construal.

5.2.2 Daily-level measures

Daily meaning, coherence, purpose, and significance were assessed using 4 single items adapted from the Multidimensional Meaning in Life Scale (Costin & Vignoles, 2020). The items were “How meaningful is your life today?” (meaning), “Today’s life feels like a sequence of connected and coherent events" (coherence), “Today, I have certain life goals that compel me to keep going” (purpose), and “Today, my life is significant” (significance).

Daily Self-concept clarity was assessed using a single item adapted from Campbell et al. (1996): “Today, I had a clear sense of who I am and what I am”, as was used by other daily dairy studies of self-concept clarity for its good match with the definition of self-concept clarity (e.g., Emery et al., 2023; Schwartz et al., 2011).

5.2.3 Covariates

Daily positive and negative affect. The sense of meaning was easily cofounded with positive affect, and people tended to rate a happy day as a meaningful day (King et al., 2006). Therefore, it is necessary to control for daily affect in order to estimate the unique contribution of self-concept clarity to the sense of meaning, independent of the influence of positive feelings. Four positive and four negative emotions (“joyful”, “satisfied”, “enjoyable”, “happy”, “sad”, “anxious”, “angry”, and “guilty”) were extracted from a validated Chinese version of Positive Affect and Negative Affect Scale (PANAS) (Qiu et al., 2008) for the simplicity of daily measurement. Multilevel confirmatory factor analysis showed that a two-factor structure fit the data well (RMSEA = 0.04, CFI = 0.97, TLI = 0.95),Footnote 3 outperforming the single-factor solution (RMSEA = 0.08, CFI = 0.88, TLI = 0.83). Consequently, we computed positive and negative affect by averaging their corresponding items separately.

Socio-demographics including gender (1 = male, 2 = female), age, and subjective socioeconomic status were assessed as control variables. We assessed the subjective socioeconomic status (SES) by showing participants a ladder that depicted different social classes in Chinese society, and asked them to indicate the position on the ladder based on their socioeconomic status (1 = the lowest, 10 = the highest).

5.3 Analytic Plan

To deal with the nested structure of daily dairy data, we determined the appropriateness of using a multilevel analysis by calculating the intraclass correlation coefficients (ICC) to assess the degree of variation occurring between- versus within-individuals for all daily-level variables. We person-mean-centered all daily-level predictors to remove between-person variance and capture within-person variance only to estimate unbiased within-person relationships, and grand-mean centered the trait-level predictors, following the recommendations by Enders and Tofighi (2007). Socio-demographic variables and daily positive and negative affect were included as covariates. Missing data were dealt with full information maximum likelihood estimation in all models.

For main analyses, a 2–1–1- multilevel mediation model and an 1–1–1- multilevel mediation model were first conducted using Mplus 8.3 to test the between-person model and the within-person contemporaneous model. We specified random slopes for the within-person paths from daily self-concept clarity to daily meaning and its three precursors. Mediation effects were tested using a Monte Carlo confidence interval at the 95% confidence level by R4.3.0.

Secondly, to test the cross-level moderating role of independent self-construal, three multilevel moderated mediation models were conducted with one of coherence, purpose, and significance as the mediator in the model separately. Similarly, the moderating effect of independent self-construal on the between-person relationships were also tested in three multilevel moderated mediation model with one precursor as the mediator in each. The multilevel moderated mediation models were conducted separately for the three precursors to to simplify the models and cater for the limited size of sample. Significant moderating effects of the direct and indirect relationship between daily or trait self-concept clarity and daily meaning were probed using simple slope analysis among those with high (M + 1 SD) and low (M − 1SD) independent self-construals.

Finally, to examine whether there are temporal effects between daily self-concept clarity, daily meaning, and daily three precursors and determined the causal directions, several bivariate dynamic structural equation models (Asparouhov et al., 2018) were applied to investigate the bidirectional effects between the main daily variables. Estimating multiple bivariate models, as compared to a multivariate model, offers the advantage of not only providing a more concise interpretation but also ensuring sufficient statistical power, particularly when the sample size is limited.

6 Results

Descriptive statistics and zero-order correlations among trait-level and daily-level variables, and ICC for daily-level variables are presented in Table 1. The ICC values for daily meaning, coherence, purpose and significance, self-concept clarity, and daily affect indicate that the use of multilevel modeling is necessary for analyzing the daily dairy data (Preacher et al., 2010).

Table 1 The descriptive statistics and correlations among main variables
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6.1 Multilevel Regression

First, we tested the between-person and within-person associations between self-concept clarity and meaning without the inclusion of the three precursors. We found that trait self-concept clarity was positively associated with meaning (b = 0.28, SE = 0.08, p = 0.001) with positive and negative affect and demographic variables controlled. It indicated that those who had a clearer and more stable self-concept reported higher sense of meaning on a daily basis. There was also a positive association between daily self-concept clarity and daily meaning (b = 0.39, SE = 0.04, p < 0.001), which suggests that on days when people experienced higher self-concept clarity than typical, they also experienced higher meaning.

6.2 Multilevel Mediation Models

Multilevel Mediation at the Between-Person Level. As shown in Table 2 and Fig. 3, at the between-person level, trait self-concept clarity was positively associated with purpose (b = 0.34, SE = 0.13, p = 0.008) and significance (b = 0.38, SE = 0.12, p = 0.002), but not coherence. Coherence (b = 0.19, SE = 0.08, p = 0.011) and significance (b = 0.40, SE = 0.08, p < 0.001), but not purpose, were positively associated with meaning. Although trait self-concept clarity was not directly associated with meaning, the indirect effect through the mediation of significance was significant (b = 0.15, SE = 0.05, p = 0.002, 95%CI [0.05, 0.27]). This suggests that individuals with high self-concept clarity experienced a greater sense of significance in their everyday lives, which in turn contributed to a heightened sense of meaning on a daily basis.

Table 2 The path coefficients of the multilevel mediation models at the between-person and within-person levels
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Fig. 3
figure 3

Between-person path coefficients

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Multilevel Mediation at the Within-Person Level. At the within-person level (see Table 2 and Fig. 4), daily self-concept clarity was positively associated with daily coherence (b = 0.31, SE = 0.05, p < 0.001), purpose (b = 0.55, SE = 0.06, p =  < 0.001), and significance (b = 0.40, SE = 0.06, p =  < 0.001). Daily coherence (b = 0.10, SE = 0.04, p = 0.013), purpose (b = 0.24, SE = 0.04, p =  < 0.001), and significance (b = 0.14, SE = 0.05, p = 0.006) were positively associated with daily meaning. The direct effect of daily self-concept clarity (b = 0.18, SE = 0.06, p = 0.002) and three mediation effects through daily coherence (b = 0.03, SE = 0.01, p = 0.039, 95%CI [0.03, 0.10]), purpose (b = 0.13, SE = 0.02, p =  < 0.001, 95% CI [0.04, 0.22]) and significance (b = 0.06, SE = 0.02, p = 0.002, 95%CI [0.02, 0.14]) on daily meaning were all significant, supporting our hypotheses H4a. Among the three mediation paths, the mediation effect through purpose was significantly larger than the mediation effects through coherence (diff = 0.10, SE = 0.03, p < 0.001) and significance (diff = 0.07, SE = 0.03, p = 0.016). It suggests that on days when individuals had higher self-concept clarity, they felt that they understood their life better, their lives were more significant, and especially they had a clearer purpose in life, which further contributed to higher sense of meaning in life.

Fig. 4
figure 4

Within-person path coefficients

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6.3 Moderation Effect of Independent Self-construal

Moderation Effects on Between-Person Relationships We examined the moderating role of independent self-construal in the single-mediation models with one precursor as a mediator at a time at the between-person level. That is, whether trait self-concept clarity was more strongly associated with higher sense of meaning on a daily basis directly and through the mediation of three precursors of meaning for those with a higher (vs. lower) independent self-construal. As shown in Tables 3, 4 and 5, independent self-construal significantly moderated the relationships between trait self-concept clarity and purpose and between trait self-concept clarity and significance, but not the relationship between trait self-concept clarity and coherence. In the moderated mediation models, independent self-construal did not moderate the direct association between trait self-concept clarity and meaning as well.

Table 3 The path coefficients of the moderated mediation models (coherence as the mediator) at the between-person and within-person levels
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Table 4 The path coefficients of the moderated mediation models (purpose as the mediator) at the between-person and within-person levels
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Table 5 The path coefficients of the moderated mediation models (significance as the mediator) at the between-person and within-person levels
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Specifically, the association between trait self-concept clarity and purpose was stronger for those with a low independent self-construal (simple slope: b = 1.65, SE = 0.63, p = 0.009) than for those with a high independent self-construal (simple slope: b = 1.31, SE = 0.48, p = 0.007). The association between trait self-concept clarity and significance was stronger for those with a low independent self-construal (simple slope: b = 2.04, SE = 0.64, p = 0.001) than for those with a high independent self-construal (simple slope: b = 1.60, SE = 0.48, p = 0.001). The mediating effects of both purpose (inddiff = 0.15, SE = 0.07, p = 0.021, 95% CI [0.02, 0,30]) and significance (inddiff = 0.24, SE = 0.09, p = 0.006, 95%CI [0.07, 0,43]) were also moderated by independent self-construal. The indirect association through purpose was stronger for those with a low independent self-construal (indlow = 0.73, SE = 0.27, p = 0.007) than for those with a high independent self-construal (indhigh = 0.58, SE = 0.21, p = 0.005). The indirect association through significance was also stronger for those with a low independent self-construal (indlow = 1.10, SE = 0.35, p = 0.001) than for those with a high independent self-construal (indhigh = 0.86, SE = 0.26, p = 0.001).

The association between trait self-concept clarity and meaning in the single regression model without the mediator was moderated by independent self-construal (interaction term: b = − 0.25, SE = 0.11, p = 0.025). The association between trait self-concept clarity and meaning was stronger for those with a low independent self-construal (b = 1.73, SE = 0.60, p = 0.004) than for those with a high independent self-construal (b = 1.38, SE = 0.45, p = 0.002). However, this moderation effect was not robust when controlling for positive and negative affect (interaction term: b = − 0.09, SE = 0.10, p = 0.375).

Cross-Level Moderation Effects on Within-Person Relationships We also tested whether the direct and mediated associations between daily self-concept clarity and daily meaning were moderated by independent self-construal. As shown in Tables 3, 4 and 5, independent self-construal only moderated the within-person association between daily self-concept clarity and daily significance. Specifically, the association between daily self-concept clarity and daily significance was stronger for those with a low independent self-construal (b = 0.52, SE = 0.07, p < 0.001) than for those with a high independent self-construal (b = 0.28, SE = 0.06, p < 0.001), which was contrary to H4b. The mediation effect was also moderated (inddiff = 0.05, SE = 0.03, p = 0.047, 95% CI [0.01, 0.11]), with the mediation effect stronger for those with a low independent self-construal (b = 0.11, SE = 0.04, p = 0.004) than for those with a high independent self-construal (b = 0.06, SE = 0.02, p = 0.007). Independent self-construal did not moderate the association between daily self-concept clarity and daily meaning in the simple regression model as well (interaction term: b = − 0.04, SE = 0.07, p = 0.520).

6.4 Temporal Effects Between Main Variables

The above analyses examined between-person relationships and within-person contemporaneous relationships (i.e., within-person relationships on the same day). Since neither of these analyses can establish causality, it is valuable to investigate temporal relationships using the daily diary data. This will provide insights into potential causal effects in real-life situations.

To investigate temporal relationships, several bivariate dynamic structural equation models were employed. The results (see Table S2 to S8) revealed significant positive autoregressive effects for daily meaning, daily self-concept clarity, daily coherence, and daily significance, but not for daily purpose. Furthermore, a significant positive cross-lagged effect was found from daily self-concept clarity to daily meaning, which suggested self-concept clarity on the previous days positively predicted meaning on the following days (β = 0.12, SE = 0.05, p = 0.014, 95% CI [0.02, 0.22]). Unexpectedly, meaning on the previous days negatively predicted self-concept clarity on the following days (β = − 0.12, SE = 0.05, p = 0.007, 95% CI [− 0.21, − 0.03]); and purpose on the previous days negatively predicted meaning on the following days (β = − 0.11, SE = 0.04, p = 0.004, 95% CI [− 0.19, − 0.03]).

7 Discussion

7.1 Self-concept Clarity as a Key Predictor of Meaning in Life

Our daily diary study among Chinese suggests that self-concept clarity plays a critical factor contributing to meaning in life. The findings provide further evidence to the previous literature that employed different research designs and cultural samples (Błażek & Besta, 2012; Hong et al., 2022; Liu et al., 2023; Shin et al., 2016) and enhance the current understanding in several ways. Firstly, the daily diary method allows us to disentangle between-person and within-person relationships. Our findings support both H1a and H1b, by showing that the levels of meaning in life were higher, not only among individuals with higher trait self-concept, but also on days when individuals felt they understand themselves more clearly than usual. It is worth noting that these results held significant after controlling for daily affect, which supports our perspectives and those of others (Baumeister et al., 2013) that self-concept clarity and meaning in life have a unique connection beyond the cofounding effect of mere positive feelings (King et al., 2006).

Secondly, our study was the first to probe the mediation process in the relationship between self-concept clarity and sense of meaning. Our mediation models showed that the between-person relationship was partially mediated by the sense of significance. Individuals with higher self-concept clarity perceived themselves as more significant or important in the world, which contributed to a higher sense of meaning. This finding provides empirical support for the association between self-concept clarity and the sense of significance, aligning with previous research on the relation of self-concept clarity to self-esteem (Campbell et al., 1996; Usborne & Taylor, 2010). The sense of significance had the strongest between-person association with meaning, consistent with recent studies highlighting its importance as a precursor of meaning (Costin & Vignoles, 2020; Martela & Steger, 2022). By contrast, the between-person mediation links through purpose and coherence were not significant. The nonsignificant linkage between trait self-concept clarity and coherence was partly because sense of coherence (i.e., “life feels like a sequence of connected and coherent events”) may not be suitable to be measured on a daily basis. Instead, it tends more to be a general evaluation of a period. In contrast, the nonsignificant linkage between purpose and meaning suggest that, at the between-person level, everyday purposes may not necessarily contribute to a sense of meaning in life for certain individuals. This indicates that these individuals may not view purpose as a crucial factor in determining meaning in life.

Regarding the within-person relationship, all three precursors exhibited significant mediation effects, along with a significant direct association between daily self-concept clarity and daily meaning. These findings provide support for H2b and align with previous theories (Adler et al., 2016; Costin & Vignoles, 2020; Gregg & Sedikides, 2017; Heine et al., 2006). The findings suggest that when individuals had a clearer understanding of themselves, they were more likely to have a purpose to strive for, perceive a sense of coherence throughout the day, feel a sense of personal importance, and ultimately experience a higher sense of meaning on that particular day.

Furthermore, the results regarding temporal relationships (one-day lagged effects) revealed that self-concept clarity from previous days had lasting impact on the sense of meaning experienced on the following days. This finding provides empirical support for the causal effect of self-concept clarity on the sense of meaning. However, coherence and significance did not significantly predict the sense of meaning on the subsequent days as anticipated in theories (Costin & Vignoles, 2020; Martela & Steger, 2022). These findings partially support our assertion that self-concept clarity forms the foundation for living a meaningful life.

Interestingly, meaning experienced on the previous days had a negative effect on self-concept clarity on the following days. Additionally, purpose also had a negative lagged effect on meaning. These results indicated that the relationships between self-concept clarity, purpose, and meaning might be cyclical rather than linear, with fluctuations being a natural part of psychological well-being. A profound sense of meaning is associated with reevaluating and exploring ones’ beliefs, values, and life goals (Kuk & Guszkowska, 2019). This reflective process, while enriching, may temporarily blur self-concept clarity as individuals integrate new insights and recover from the mental and emotional engagement with these meaningful experiences (Csank & Conway, 2004). Engaging intensely in purposeful activities may lead to a temporary resource depletion (Baumeister et al., 1998), affecting one’s ability to derive meaning the next day (Längle, 2003). High engagement in specific purposes might also momentarily limit broader contemplation necessary for experiencing meaning (Staudinger, 2001). These results highlighted the complexity of the relationships between self-concept clarity, purpose, and meaning, suggesting that fluctuations are part of a normal psychological process. To better understand these unexpected effects, future researchers could collect daily diary data over extended periods of time and utilize advanced statistical methods, such as multilevel graphical network models (Epskamp, 2020). These models enable the estimation of both temporal and contemporaneous relationships simultaneously within a unified framework. Our limited sample size and relatively short investigation period prevented us from conducting such sophisticated analyses.

7.2 The Moderating Role of Independent Self-construal in a Collectivistic Culture

Our study also contributes to understanding the role of self-concept clarity in the experience of meaning in life within a collectivistic cultural context. Contrary to some previous theories and studies that suggested self-concept clarity might be less relevant in collectivistic cultures (Campbell et al., 1996; Markus & Kitayama, 1991; Shin et al., 2016), our findings demonstrate that self-concept clarity is indeed an important factor for experiencing a meaningful life among a Chinese sample. These results suggest that the positive impact of self-concept clarity on meaning in life may be universal rather than culturally specific.

Furthermore, we identified a significant moderation effect of independent self-construal, which refers to a self-view that emphasizes the distinction between oneself and others, prioritizes personal needs, desires, and characteristics, and pursues self-actualization (Markus & Kitayama, 1991). Specifically, the associations between trait self-concept clarity and significance, as well as between trait self-concept clarity and purpose, were stronger among individuals with a low independent self-construal at the between-person level. Similarly, at the within-person level, the association between daily self-concept clarity and daily significance was stronger for individuals with a low independent self-construal. These moderation results contradict our cultural relativity hypothesis that self-concept clarity should be more important for individuals who emphasize the autonomous and unique self. Instead, our results suggest the universality of the importance of self, as described in the self-determination theory (Deci & Ryan, 2000). Self-concept clarity was not unimportant to those with a lower level of independent self; in fact, it matters to them even more. This finding contradicts previous studies that indicated a stronger relationship of self-concept clarity or self-consistency with self-esteem or well-being among those with a higher independent self-construal (Campbell et al., 1996; Cross et al., 2003). The nuanced mechanisms and explanations underlying these sophisticated moderation effects require further investigation.

Lastly, our study has practical implications for collectivistic cultural contexts, such as China. The findings demonstrated that self-concept clarity is particularly beneficial in fostering a sense of meaning in life, even in a cultural context that downplays independent self-construal and de-emphasizes individuality and self-expression. Based on these findings, practitioners can promote self-focus and self-reflection among Chinese young people to develop a clearer and more stable self-concept that serves as a guiding force in pursuing meaningful lives. Such interventions have the potential to alleviate feelings of meaninglessness and contribute to individuals' overall well-being.

7.3 Limitations and Future Directions

The current study has several limitations that should be acknowledged. First, while the use of the intensive longitudinal method, specifically the daily diary method, allows for a better understanding of the causal processes by analyzing contemporaneous and lagged effects, future studies employing experimental designs would be warranted to cross-validate these findings. Second, although we extended the current literature by examining a sample within a collectivistic context (i.e., China), we did not include and compare it with other samples from individualistic cultures to generalize the conclusions. Instead, we only measured independent self-construal as an individual-level indicator of collectivism versus individualism within the studied sample to infer possible cultural influences. Therefore, further cross-cultural studies are recommended to provide a more accurate investigation of the role of culture.

Third, we relied solely on self-report measures of self-concept clarity, which are subjective and heavily reliant on self-introspection (Csank & Conway, 2004). This may introduce measurement bias, as individuals' ability to engage in self-introspection can vary. Additionally, the use of self-report measures may have inflated the association between self-concept clarity and meaning in life due to common method bias. Recent researchers have made a distinction between subjective and objective aspects of self-concept clarity (Guerrettaz & Arkin, 2016). A previous study demonstrated that the relationship between meaning in life and self-concept clarity may be attenuated when using an objective measurement of self-concept clarity (Schlegel et al., 2009). Therefore, it would be worthwhile to examine and compare subjective and objective self-concept clarity in future studies to gain a better understanding of their distinct roles.

7.4 Conclusion

This study underscores the significance of self-knowledge in fostering a meaningful life within a collectivistic cultural context. By utilizing a daily diary method, the study contributes to the literature by enhancing the ecological validity of the findings. Our multilevel analysis reveals that daily self-concept clarity has a positive influence on meaning in life, with coherence, purpose, and significance serving as mediating factors on the same days. Additionally, individuals with higher trait self-concept clarity consistently experience a heightened sense of meaning in their daily lives, and this association is mediated by the sense of significance. These positive relationships are particularly pronounced among individuals with a lower level of independent self-construal, emphasizing the importance of cultivating a clear and stable self-concept even in a collectivistic cultural context that places less emphasis on individuality. These findings hold practical implications, as interventions aimed at promoting self-understanding could be an effective strategy for addressing the prevalent issue of "hollow heart disease" and nurturing a greater sense of meaning among youth in China.