Newsletter research reveals the rate of unique baby names in Japan increased over the 40 years since the 1980s

Previous research has analyzed baby names displayed by private companies and indicated that the rates of unique names increased in Japan between 2004 and 2018 (Ogihara, 2021; Ogihara et al., 2015). However, changes over a longer period were not analyzed because of the lack of a comprehensive and systematic database of baby names in Japan. Therefore, it was unclear whether this increase in unique names was recent or had occurred before the 2000s. There was a possibility that the increase in unique names occurred only after the 2000s.

Examining whether the rates of unique names increased for a longer period provides a better understanding of not only historical changes in names and naming practices, but also cultural changes toward greater individualism which emphasizes uniqueness and independence.

To this end, Assistant Professor Yuji Ogihara of Tokyo University of Science and Atsuki Ito of Hitotsubashi University collected baby names from municipality newsletters and investigated historical changes in the rates of unique names in Japan over a longer period. Municipalities share important information such as major events (e.g., sports activities, lecture meetings), services (e.g., educational, medical), and basic statistics (e.g., financial, population) in newsletters. In these newsletters, the names of persons who are born, die, and marry in each municipality are listed.

For their study, the researchers collected municipality newsletters that fulfilled some criteria. The municipalities surveyed were geographically diverse. They were located all over Japan, from the southern part (Kyushu) to the northern part (Hokkaido). Some municipalities were located near the coast, while others were inland. The municipalities were also demographically diverse. They were located in both rural and urban areas.

The researchers analyzed 58,485 baby names published in these municipality newsletters between 1979 and 2018. They calculated the rates of the names that were not duplicated in each of the municipalities in each year. Then, they analyzed their historical changes. Furthermore, they calculated the rates of unique names not only within a given year (e.g., 2000) but also within a three-year unit (the target year, the year before it, and the year after it; e.g., 1999, 2000, 2001), and performed the same analysis.

They found that the rates of unique names increased within both time frames. Thus, unique names increased not only after the 2000s, but also from the 1980s for 40 years. This result shows that parents increasingly gave unique names to their babies and that Japanese culture increasingly emphasized uniqueness and independence for the 40 years, providing further evidence of the rise in uniqueness-seeking and individualism in Japan. This finding is also consistent with prior studies showing the rise in individualism in other aspects such as family structure and values.

Moreover, the findings reported in previous research (Ogihara, 2021; Ogihara et al., 2015) were replicated in this study: unique names increased in Japan in the 2000s and 2010s. In addition, the rates of unique names increased more rapidly for girls than for boys. This result may suggest that parents came to have stronger hope for their daughters to become unique and independent than for their sons.

This means that the same phenomena were observed in a dataset different from that analyzed in previous research, indicating that the finding of an increase in unique names in Japan is robust. These findings were made available online on April 28, 2022, and published on June 21, 2022, in volume 3 of the international journal Current Research in Ecological and Social Psychology.

This study reveals an increase in the rates of unique names in Japan via an analysis of baby names published in municipality newsletters. Unique names increased from at least the 1980s in Japan. It shows that Japanese culture has changed toward greater individualism which emphasizes uniqueness and independence. Therefore, this research contributes to the understanding of changes in not only Japanese names and naming practices but also Japanese culture.

Assistant Professor Ogihara plans to continue investigating the historical changes in names and naming practices in Japan. In the near future, he aims to examine whether these changes have continued in the last few years recently and how COVID-19 has affected naming practices in Japan.