4.1 Alexithymic tendencies in Japanese adolescents
The present study investigated Japanese adolescents from junior high school to university and sought to clarify the changes that alexithymic tendencies exhibit. We will start by discussing differences in ASA total scores based on the academic year of participants. ASA and TAS-20 have same subscales, which comprise the same number of items with different expressions of individual items, but the average ASA scores (53.92 for males and 54.83 for females) herein were considerably similar with the average TAS-20 score for participants aged 14–19 years old in the study by Moriguchi et al. [6]. The mean values obtained from by Moriguchi et al. [6] (48.2 for males and 48.4 for females; the participants were 14–84 years old) indicate that the ASA total scores exhibit a higher trend in adolescents than in adults and that this level will start to decline after individuals reach their twenties. If we compare trends in the ASA total scores obtained in this study with values obtained in previous studies in other countries [24, 25, 28], we find that the level of alexithymic tendencies around the age of 12 is similar, but previous studies demonstrate a subsequent downward trend. In contrast, the scores for Japanese participants showed a tendency to remain at a high level into and beyond the second-year of junior high school. The results of this study appear to be similar to the tendency of Korean adolescents [26], wherein the alexithymia score does not change during adolescence.
Moreover, in terms of changes in the subscales, DIF and DDF were measured at higher levels among high school students than in previous studies [24, 25, 28]. The EOT subscale showed a downward trend similar to that of other countries [24, 25, 28] and a particularly large decline in scores was observed among high school students in Japan.
According to Moriguchi et al. [6], DIF and DDF tend to decrease from adolescence to the thirties, and EOT tends to increase with age from adulthood onward. Moriguchi et al. [6] also state that alexithymia has two different developmental pathways: the DIF/DDF pathway and the EOT pathway. Moriguchi et al. [6] argue that as EOT is more related to negative attitudes toward coping with stress than an interest in inner emotions, the increase in EOT with aging may reflect a weakening interest in seeking new coping methods in comparison with younger age groups. Thus, the results of the present study may reflect a growing interest in the inner self and the emotional aspects of phenomena in Japanese adolescents.
In contrast, we speculate that DIF and DDF were affected by the temporary difficulty that individuals experience in identifying and expressing emotions as their interest in such emotional aspects increases. A link between depression and alexithymia has been identified in several studies [35]. According to the Cabinet Office of the Government of Japan [36], young people between the ages of 13 and 29 in Japan have lower self-esteem and basal mood than young people in other countries. This suggests that alexithymic tendencies in adolescence may be higher than those in other countries. In a study of adolescents in South Korea, while the alexithymia score (mean TAS-20K = 45.69) was rather different from those of the present study (mean ASA = 54.38), an increase in DIF was observed with the increasing age, as in the present study. A study found that alexithymia scores were significantly higher in university students with roots in Asian countries than in European–American university students [37]. This is said to be related to cultural values that encourage hiding emotions, which Asian parents instill in their children through home education [37]. Concerning Japanese adolescents, while there is no large difference in alexithymia scores in the first half of adolescence (junior high school students) compared to Europe and the United States, among high school students, the difference between Europe and American and Japanese people becomes greater. From the first year of high school in Japan, students are more likely to face stress, anxiety, and frustration about the experience of making their own career choices after completing compulsory education, as well as changes in their friendships and living environment, and changes relating to becoming independent from their families. The authors surmise that compared with other countries, young people in Japan may find it more difficult to express their emotions and thoughts, which as a result, may become internalized and further complicated. They may also tend to face difficulties in identifying their emotions and thoughts and communicating them in a manner that enables them to be understood by others.
The results of this study may have captured developmental changes in alexithymic tendencies among Japanese adolescents, especially concerning the particular influence of Japan’s cultural sphere and the related temporary increase in alexithymic tendencies. While the ASA total scores of Japanese adolescents were at a similar level to the alexithymia scores in previous studies [24, 25, 28], the developmental trends of the subscales suggest that the quality of alexithymic tendencies may differ between the early and late teens.
In addition, the alexithymic tendencies of Japanese adolescents consistently showed higher ASA total scores in females than in males. In the subscales, females were found to have significantly higher DIF and DDF, with males exhibiting significantly higher EOT, although these differences were small effect sizes ranged d = .10–.26. This is consistent with the results of previous studies. For example, the results of a large-scale survey in Japan (Moriguchi et al., 2007) and the results of a study [6] conducted on Finnish youths showed similar gender differences in terms of DIF and EOT [25]. In a sample of Japanese adolescents, gender differences in terms of DIF and EOT were found to be consistent throughout adolescence and were not affected by development. However, considering that a gender difference in DDF was not found in Moriguchi et al. [6], nor in previous studies with adolescents [24, 25], it is possible that this difference between gender is peculiar to Japanese adolescents.
4.2 Alexithymic tendencies and somatic complaints
The present study examined the effect of alexithymic tendencies on somatic complaints in Japanese adolescents and concluded that alexithymic tendencies have the effect of exacerbating somatic complaints. DIF was found to particularly affect somatic complaints. This result is similar to that of the multiple regression analysis conducted at a primary school by Rieffe et al. [15]. A study of adults [8] also reported that DIF was most strongly associated with somatic complaints. Therefore, the results of the present study support the findings of previous studies.
The main effect of DDF was observed in male students at junior high school and high school students, and no effect was observed in university students. In Rieffe et al. [15], the effects of DIF and DDF were found in primary schools (mean age 11 years), whereas the effects of DIF was mainly identified in secondary schools (mean age 13 years). From this, we can infer that the effect of DDF on somatic complaints is something that disappears as individuals develop. Although DDF was significantly higher in female participants, the effect of DDF on SCL was found mainly in males. This may be because Japanese females tend to more actively disclose when they experience unpleasant emotions and they also try to resolve the problem directly, whereas males are more self-defensive and are less likely to respond directly than females [38–40].
With regards to EOT, while caution is required in interpretation due to insufficient reliability, in the present study, the relationship between EOT and somatic complaints was found only in female participants at high school, suggesting that EOT is a factor that lacks a broad significance in this regard. A study of adults [19] that examined the relationship between alexithymic tendencies, perception of physical disorders, and desired care reported that EOT was significantly higher among those who rarely used outpatient facilities and did not seek psychotherapy than among those who used such facilities and sought psychotherapy more often. While EOT may not directly affect somatic complaints, it may be a factor that exacerbates issues through its effect on subsequent coping behaviors and support needs. Therefore, future studies should examine the indirect effects of EOT on health, including coping behaviors, rather than its direct effects on the senses through physical symptoms and other factors.