All normally developing children possess the innate knowledge to attain full linguistic proficiency in their first language. In contrast, adults exhibit considerable variation in their ultimate attainment of second language proficiency. The Critical Period Hypothesis offers a plausible framework for explaining the disparities observed between first and second language acquisition. This hypothesis posits the existence of a finite developmental span during which the acquisition of a language to a native-like level is feasible; subsequent to this critical period, the capacity for language acquisition diminishes. Numerous scholars have dedicated their efforts to investigating the veracity of this critical period phenomenon. In light of its potential existence, this paper explores its implications for first language acquisition and its ramifications for second language acquisition. With a primary emphasis on the domain of second language acquisition, this study delves into the rationales underlying the assumption that humans may be subject to a critical period for language acquisition. Furthermore, it scrutinizes the extent to which the principles governing acquisition in a second language environment may or may not be applicable to the acquisition of a second language in a distinct foreign language environment.

As a result of the Japanese/English IRT test of more than 2,500 university freshmen, students with high English proficiency at Eiken level 2 or above almost had Japanese proficiency at level 3 or above, and students with Japanese proficiency at junior high school level. It has been found that in order to achieve a high level of English proficiency, it is necessary to first develop Japanese proficiency. Therefore, the authors implemented and confirmed the effectiveness of a new English learning program for Japanese university students that included Japanese language instruction and the development of communication and intercultural skills.

This paper presents the findings of a university-wide survey of BEVI-j (Beliefs, Events, and Values Inventory, a psychological measurement tool), in a medium-sized Japanese university. In addition to the results, the paper considers the potential value of BEVI-j for future studies. Yokohama National University has introduced BEVI-j university-wide since 2021, ahead of other universities in Japan. The results have confirmed that BEVI-j is not only effective in assessing the impact of overseas study programs but also in making students aware of their own beliefs and values, which students may have difficulty in their conscious recognition. The data obtained by the use of the university-wide survey has enabled the identification of some tendencies, such as gender-based differences, differences between domestic and international students, and challenges related to global talent development. The findings of this study cannot be simply generalized to the majority of Japanese university students. However, the results will provide a valuable reference for future research.

As of 2023, after the COVID-19 pandemic has subsided, some universities are starting to resume overseas training by dispatching students. For the past few years, both students and universities have been waiting for an environment in which they can freely study abroad, as was the case before 2019. On the other hand, the question emerges regarding what will happen to online overseas training, which has rapidly developed in the last few years. Therefore, in this paper, the author considers the advantages, disadvantages, results, and future of online overseas programs based on a practical report on an online overseas program conducted in the spring of 2022 and a questionnaire survey of university students who participated in the program. The results indicate that, even though it was a short-term online overseas program lasting two weeks, points such as Intercultural approach (-avoidance) tendency, Ethnocentrism, Interest in foreign affairs, Having things to communicate, Independence, Cooperation, Cross-cultural understanding, and Knowledge and education effect increased.

Since 2010, the Japanese government has tried to increase the number of local students who study abroad to further nurture so-called global talents in the 21^st century. Although the number dropped dramatically due to the widespread COVID-19 pandemic in 2020-2022, those numbers started to recover in the middle of 2022. However, scientific evidence is limited in terms of showing that study abroad programs, especially short-term ones, provide learning outcomes to the extent that students become global talents in such a short period of time. This paper provides evidence of short-term study abroad programs' learning outcomes based on the global research tool called BEVI that is useful regardless of the length of studying period. The sample included students of University A, a national university in Japan, who studied at the University of Hawaii, Manoa, USA, for two weeks in February 2023. The results of BEVI tests show that, among 17 indicators, global resonance increased the most after the program. In this sense, a study abroad program, however short it is, could be significant. The research also shows that the upper cohort, eight students who had been ready to study abroad, grew most in the three most important indicators.