Taekwondo is an internationally established martial art, included in the Olympic Games, and is practiced today by millions of people in more than 200 countries (International Olympic Committee, 2021). Despite some controversies regarding its origin and history, Taekwondo is known to have evolved from a form of unarmed military training of ancient kingdoms of the Korean peninsula, including Hwarang
, an elite scholar-warrior group of male youth in the Silla kingdom 
. Though it originated from a fighting system for self-defense, Taekwondo is enjoyed as a sport effective for health promotion and self-discipline, regardless of age and gender. In addition to the physical and psychological benefits of training in a sport, it has also been widely practiced as a vehicle for developing practitioners’ mental strength and ethics 
. Distinctively, Taekwondo places a significant value in positively affecting practitioners’ behavior and spirit through the training process 
The name Taekwondo is derived from the Korean words “tae”, meaning feet or kick, “kwon”, meaning fist or punch, and “do”, meaning path or realization. As its name represents, the Taekwondo spirit can be described by the concept of “do.” This meditative aspect of the forms in Taekwondo includes learning Taekwondo etiquette and the training of minds, encouraging practitioners to achieve self-realization through advancement of both body and mind, and to apply it in their lives 
. To shape “do,” Taekwondo philosophy teaches five core tenets: courtesy, integrity, perseverance, self-control, and indomitable spirit 
. Historically, these lessons have been associated with pursuing peace, having respect to one another, and standing in solidarity with individuals weaker in body, mind, and spirit 
. These tenets are consistent with the principle that Taekwondo skills should be used only with good and peace as the ultimate goals.
One of the reasons behind Taekwondo’s global expansion and popularity over the years may be its positive impact on multiple aspects of personality development such as values, beliefs, self-development, manners, leadership, social skills, and confidence 
. For decades, studies have reported that it has beneficial effects on trainees’ social development, especially children and adolescents, by improving personality, manners, and behavior, and contributes to adaptation to and satisfaction with school life 
In terms of personality development, Lim 
reported that a 12-week Taekwondo intervention for elementary school 2nd-4th graders resulted in significant improvements in leadership, confidence, and manners. Similarly, preschoolers who participated in 15 sessions of a physical activity program using Taekwondo over eight weeks demonstrated higher scores on personality assessments in the lifestyle, self-establishment, sense of community, physical development, and sociality subscales compared with the controls 
Taekwondo training has long been reported to be effective in enhancing the social traits of practitioners 
. Sociality, a distinct human trait that prompts the need to associate with social groups, is a fundamental characteristic of survival and coexistence with others. According to a study that investigated the correlation between self-regulation and sociality in elementary school students practicing Taekwondo, depending on the duration, the training period explained differences in diligence, interpersonal relationships, and responsibility, suggesting that regular Taekwondo training has a positive effect on social development 
. They also found that self-regulation affected sociality factors such as diligence, responsibility, interpersonal relationships, and cooperation. Furthermore, in a recent study by Bae and Roh 
, who conducted a 16-week Taekwondo intervention designed for children from multicultural families, it was observed that overall sociability scores improved after the intervention, with reduced scores on feelings of isolation. These findings indicate that individuals learn perseverance and self-control in Taekwondo training, and internalization of these traits may contribute to social development and adaptation to the group.
Taekwondo has been well received by schools and parents who expected it would assist students in adapting to school life and in forming desirable etiquette and character during a critical period of development. Many of today’s young students are forced to live a uniform and passive life within the framework set by adults, and experience social disconnection due to lack of family integrity, highly competitive education, and school violence, along with increased time spent in online activities 
. In this context, Taekwondo has been discussed as a possibly effective option for many psychological and social problems, such as the school violence, bullying, and delinquency to which children and adolescents are exposed 
2. Psychosocial Effects of Taekwondo Training
Taekwondo training had small to medium effects on psychosocial factors.
Taekwondo had a positive effect on sociality in the subfactors of cooperation, law-abidance, leadership, responsibility, sociability, and stability.
A meta-analysis of studies examining Taekwondo’s effect on sociality revealed that Taekwondo training in the long term might be effective for an individual’s social development. However, due to the relatively small effect size and the study type (i.e., cross-sectional) of the literature synthesized in this meta-analysis, caution needs to be taken to avoid overestimating the link between them. Furthermore, Taekwondo’s overall effect on sociality subfactors such as activity, autonomy, and capability were not significant.
We found that, although some studies reported significant correlations between the sociality outcomes of Taekwondo training students and their demographic characteristics, such as the parents’ education and income level 
, none of these studies further assessed the effects of Taekwondo on the linkage between socioeconomic status and social development. As underserved groups are often known to be more sensitive to exercise effects, having greater room for improvement 
, future studies are encouraged to explore whether Taekwondo training’s effect on social development differs depending on socioeconomic factors.
Taekwondo training had a positive impact on character in the subfactors of sense of community, consideration, emotionality, leadership, propriety, living, self-establishment, and self-esteem.
The principle that Taekwondo brings about positive character development in trainees, especially children, is closely related to the solemn and educational atmosphere of Taekwondo academies and training program content that is intentionally planned and delivered by the Sabum-nim (i.e., master instructor) 
. As part of the training, they usually include elements of character education such as greeting, etiquette, respect, consideration, rules of conduct, etc. For this reason, regular participation in Taekwondo in the long run not only contributes to personal growth but also to relationships with others, as internalization of these lessons can be transferred to daily life in school and at home 
. A trainee who has earned a black belt after long and difficult training feels a strong sense of achievement, and these juniors are often given the role of instructor assistants during training, helping other trainees with Poomsae or leading Gihap (i.e., a shout of concentration). These experiences enhance the trainees’ leadership and consideration of others, as well as fostering self-esteem and self-efficacy 
Taekwondo training had a positive effect on etiquette in all of the tested subfactors (deportment, greeting, interpersonal etiquette, language, listening, phone etiquette, etiquette in public places, dining etiquette, and visiting etiquette).
Proper etiquette is an important component in Taekwondo, as reflected in the saying “Taekwondo begins with manners and ends with manners.” Taekwondo instructors continuously educate the trainees to be polite, behave properly, and show respect to others, which becomes a habit expressed in the trainee’s life at home and at school, and these basic behaviors develop into good manners. Trulson 
argued that the traditional form of Taekwondo, which emphasizes martial arts philosophy, is effective for positive youth development. Previous studies also support that the traditional Taekwondo as a martial art has greater psychosocial benefit compared to modern Taekwondo as a sport 
. Considering that the purpose of traditional Taekwondo is not about beating the opponent or winning the match, but rather to improve self-control, it is understandable that training programs including education in the mental and philosophical aspects of Taekwondo might be more useful for psychosocial development than the game-oriented style of Taekwondo training. The differential training effects of these two distinct approaches should be explored in depth in future studies.
2.4. School Life Adjustment
Taekwondo had a positive effect on school life adjustment in the subfactors of learning, friendship, rule compliance, and teacher relations. Students who took part in Taekwondo training were shown to have higher scores on the measures of school life adjustment compared to non-trainees. These results imply that Taekwondo training taking place in a peer group may facilitate socialization of the student trainees, which ultimately contributes to school life where they spend a great deal of time with peers.
Furthermore, studies have reported that individuals who train in Taekwondo have better self-control compared to non-trainees, with certified trainees demonstrating even better self-control (reference). In the study by Choi 
, children with better self-control in attention, composure, rule compliance, and interpersonal relationships showed better adaptation to school life. These findings suggest that enhanced self-control through Taekwondo training is closely related to school life adjustment.
It appears that trainees have opportunities to learn attitudes and values such as sportsmanship, rule-observance, self-discipline, role sharing, and cooperation during Taekwondo practice, which are highly effective and important skills for adapting to the school community and establishing a satisfactory life at school. Future research will need to investigate its effect on school life adjustment using randomized controlled trials, with varying lengths and trainees’ socioeconomic characteristics taken into consideration.
In summary, Taekwondo training has positive effects on psychosocial factors such as sociality, character, etiquette, and school life adjustment. Specifically, Taekwondo trainees exhibited significantly higher self-assessed scores on cooperation, law-abidance, leadership, responsibility, sociability, and stability among the subfactors of sociality. In the character subfactor, Taekwondo trainees were found to have a higher sense of community, consideration, emotionality, leadership, propriety, living, self-establishment, and self-esteem. In terms of etiquette, Taekwondo trainees had better qualities in terms of deportment, greeting, interpersonal etiquette, language, listening, phone etiquette, etiquette in public places, dining etiquette, and visiting etiquette. Finally, the improved psychosocial characteristics seem to be associated with better school life adjustment, as evidenced by higher scores on learning, friendship, rule compliance, and teacher relations in Taekwondo training students relative to non-trainees.