The study participants were 119 Japanese undergraduate and graduate students (43 women, 76 men; mean age ± standard deviation: 22.02 ± 1.35 years; age range: 19 - 25 years). Participants were selected randomly from students of Kyushu University. All participants provided informed consent after receiving an explanation of the purpose of the study. The study protocol was approved by the ethics committee.

Participants were asked to complete the following two questionnaires: the Japanese versions of the IRI (Sakurai, 1988) and the PWB (Nishita, 2000) . All participants were instructed to read the questionnaire items carefully and choose the responses that best described themselves. Similar to the original, the Japanese version of the IRI is composed of 28 items. The Japanese version of the PWB was modified to comprise 43 items, based on the original (Ryff & Keys, 1995) . All items on the IRI were rated on 4-point Likert scale (1 = “does not describe me very well” to 4 = “describes me very well”), and all items on the PWB were rated on a 6-point Likert scale (1 = “does not describe me very well” to 6 = “describes me very well”). We then calculated the scores for each subscale on both the IRI and the PWB, as well as the sum of all items on the PWB.

Examples of items from each of the four IRI subscales are as follows: perspective taking, “I sometimes try to better understand my friends by imagining how things look from their perspective”; fantasy, “After seeing a play or movie, I have felt as though I were one of the characters”; empathic concern, “I often have tender, concerned feelings for people less fortunate than me”; and personal distress, “When I see someone who badly needs help in an emergency, I go to pieces”.

Examples of items from each of the six PWB subscales are as follows: Personal growth, “For me, life has been a continuous process of learning, changing, and growing”; purpose in life, “I have a sense of direction and a purpose in life”; autonomy, “My decisions are not typically influenced by what everyone else is doing”; self-acceptance, “In general, I feel confident and positive about myself”; environmental mastery, “I am quite good at managing the many responsibilities of my daily life”; and positive relationships with others, “I know that I can trust my friends, and they know that they can trust me”.

Analyses were conducted using SPSS software (Version 17, SPSS Inc., Chicago, IL, USA). First, correlation between IRI and PWB scores were calculated as a preliminary analysis (Pearson correlation coefficient). Second, stepwise regression analyses were conducted with IRI scores (four subscales) as predictor variables and PWB scores (total score and six subscales) as predicted variables. Statistical significance was set at (p < 0.05).

The mean (and standard deviation) IRI and PWB scores are shown in Table 1. Cronbach’s alpha was acceptable

Note: N = 119. SD = Standard deviation. ^aCronbach’s Alpha. ^bCorrelation between age and traits. ^cCorrelation between gender and traits (0 = male, 1 = female). No significant correlation was shown for age and gender.

for all IRI and PWB subscales (all ? > 0.7) except for fantasy (? = 0.689) and empathic concern in the IRI (? = 0.583). No age- or sex-related effects on IRI or PWB scores were found (all p > 0.05).

The correlations between IRI and PWB scores are shown in Table 2. All data were subjected to regression analysis. Significant and positive intercorrelations were found between all IRI items (p < 0.05) except for perspective taking and personal distress (p = 0.344), and between all PWB items (p < 0.05) except for autonomy and positive relationships with others (p = 0.061).

The results of stepwise regression analyses are shown in Table 3. The total PWB score was negatively predicted by personal distress and positively predicted by perspective taking. This difference was also evident in the PWB subscales: perspective taking positively predicted personal growth, purpose in life, and environmental mastery, whereas personal distress negatively predicted autonomy, self-acceptance, and environmental mastery. Neither fantasy nor empathic concern predicted psychological well-being. In addition, positive relationships with others was not predicted by any IRI subscale.

The positive relationship found between perspective taking and psychological well-being in the present study was not high, only accounting for less than 6% of the variance (Table 3); however, it does suggest that perspective taking plays an important role in psychological well-being, which supports the findings of previous studies (Shanafelt et al., 2005: Thomas et al., 2007) . The PWB subscales predicted by perspective taking were personal growth, purpose in life, and environmental mastery. This suggests that perspective taking and psychological well-being might be positively related because perspective taking and the three PWB subscales are associated with cognitive efforts to regulate emotion and behavior. Taking the perspective of others indicates suppression of the perspective of the self, and therefore helps reduce selfish behavior or impulsive emotions through cognitive effort. Moreover, humans can take the perspective of not only others, but also their future selves (Gazzaniga, 2008) . This suggests the possibility that perspective taking might help individuals control their behavior or manage their environment to achieve a better future self. This interpretation is also in line with the close relationship between well-being and the cognitive regulation of emotions such as reappraisal (John & Gross, 2004) .

Note: N = 119. Pearson correlation. ^*p < .05, ^**p < .01.

Note: N = 119. ^*p < 0.05, ^**p < 0.01, ^***p < 0.001.

As mentioned in the introduction, previous studies have reported different results regarding the association between empathic concern and psychological well-being (Shanafelt et al., 2005; Thomas et al., 2007) . No association was found between empathic concern and psychological well-being in the present study, suggesting the absence of a relationship between psychological well-being and having warm feelings and compassion for others; this supports the findings reported by Shanafelt et al. (2005) . Specifically, given that both empathic concern and positive relationships with others reflect concern for others, it is interesting that empathic concern did not predict positive relationships with others. This might be due to differences between the two subscales, in that empathic concern tends to focus on emotional responses (e.g., feeling sorry for or sympathy toward others), while positive relationships with others tends to focus more on actual behaviors (e.g., enjoying conversation with others). In addition, empathic concern reflects responses to others in “negative” situations (i.e., unfortunate others), while positive relationships with others does not specifically depend on whether others are in a “negative” or a “positive” situation. Taken together, the findings of the present study that empathic concern is not associated with positive relationships with others suggests that emotional responses such as sympathy for others in negative situations do not have a direct effect on the development of positive relationships with others.

Furthermore, the absence of an association between psychological well-being and fantasy also suggests the lack of a relationship between psychological well-being and the trait of becoming immersed in a fictional character. This might be because the object of immersion reflected in the fantasy subscale is “fictional” and therefore not reality. However, the relationship between psychological well-being and the fantasy subscale of the IRI remains unclear, and further studies are needed to confirm this result.

We found that personal distress negatively predicted psychological well-being―specifically, autonomy, environmental mastery, and self-acceptance. As mentioned in the introduction, one of important differences between empathy and personal distress is that empathy requires a clear distinction between the self and the other, while personal distress does not (reviewed in Decety & Lamm, 2006, 2009; Singer & Lamm, 2009 ). Therefore, a blurred distinction between the self and the other seems to be associated with less independence, a decreased ability to control the self and the environment, and a more negative attitude toward the self. This reconfirms the importance of the cognitive aspect of empathy for the improvement of psychological well-being as mentioned above, since distinction between the self and the other requires cognitive effort. In addition, it is worthwhile to emphasize that personal distress negatively predicted self-acceptance. Self-acceptance has been the most frequently mentioned criterion of well-being and is closely related to mental health (Ryff, 1989) . Furthermore, previous studies have indicated that personal distress is closely related with depression (O’Connor, Berry, Weiss, & Gilbert, 2002; Thoma, Zalewski, von Reventlow, Norra, Juckel, & Daum, 2011) , neuroticism (Bartholow, Sestir, & Davis, 2005; Lee, 2009) , and alexithymia (Grynberg, Luminet, Corneille, Grèzes, & Berthoz 2010) . Taken together, personal distress is thought to be an effective indicator of mental health.

The present study did have several limitations. First, the sample size was quite small. Second, the reliability of fantasy and empathic concern was low. Future studies are therefore needed to reexamine the present findings.

In addition, the opposite effects of perspective taking and personal distress on psychological well-being poses the question of whether individuals with a high level of personal distress can improve their psychological well-being by making a cognitive effort to take the perspective of others. Furthermore, regarding the relationship between empathy and psychological well-being, whether empathy predicts not only psychological well-being, but also objective status of well-being (e.g., maintaining a number of close friends or a good relationship with the family) remains unclear. These issues will need to be addressed in future studies in order to clarify the relationship between empathy and well-being.