The herbivore’s dilemma: Trends in and factors associated with heterosexual relationship status and interest in romantic relationships among young adults in Japan—Analysis of national surveys, 1987–2015

Abstract

Background It has been suggested that an increasing proportion of young adults in Japan have lost interest in romantic relationships, a phenomenon termed “herbivorization”. We assessed trends in heterosexual relationship status and self-reported interest in heterosexual romantic relationships in nationally representative data. Methods We used data from seven rounds of the National Fertility Survey (1987–2015) and included adults aged 18–39 years (18–34 years in the 1987 survey; sample size 11,683–17,675). Current heterosexual relationship status (married; unmarried but in a relationship; single) was estimated by sex, age group and survey year, with singles further categorized into those reporting interest vs. no interest in heterosexual romantic relationships. Information about same-sex relationships were not available. Results Between 1992 and 2015, the age-standardized proportion of 18-39-year-old Japanese adults who were single had increased steadily, from 27.4 to 40.7% among women and from 40.3 to 50.8% among men. This increase was largely driven by decreases in the proportion of married women aged 25–39 years and men aged 30–39 years, while those in a relationship had increased only slightly for women and remained stable for men. By 2015, the proportion of single women was 30.2% in those aged 30–34 years and 24.4% in those aged 35–39 years. The corresponding numbers for men were 39.3% and 32.4%. Around half of the singles (21.4% of all women and 25.1% of all men aged 18–39 years) reported that they had no interest in heterosexual romantic relationships. Single women and men who reported no interest in romantic relationships had lower income and educational levels and were less likely to have regular employment compared to those who reported such an interest. Conclusions In this analysis of heterosexual relationships in nationally representative data from Japan, singlehood among young adults had steadily increased over the last three decades. In 2015 around one in four women and one in three men in their thirties were unmarried and not in a heterosexual relationship. Half of the singles reported no interest in romantic relationships and these women and men had lower income and educational levels and were less likely to have regular employment.

Salaries, degrees, and babies: Trends in fertility by income and education among Japanese men and women born 1943–1975—Analysis of national surveys

“…Moreover, men born in 1971–1975 and who were unemployed or had part-time or temporary employment were more likely to be childless as compared to those with regular employment. In previous studies, lower income and precarious employment among men have been strongly associated with a higher likelihood of having no heterosexual experience [ 21 ], being single [ 5 ] and being unmarried [ 24 ]. Given that heterosexual relationships are the most common type of childbearing union and over 95% of the children are born to married couples in Japan, the association between lower income and lower fertility in our study may not be surprising [ 25 ].…”

“…The final study population included 16 728 men (13 786 married) and 17 628 women (14 896 married); the number of participants by birth cohort and survey are shown in S1 File (S3 Table). Sample weights were used to adjust for differential probabilities of non-response, by age, sex, and marital status and were calculated based on data from the Population Census of Japan, as described in detail elsewhere [ 5 , 21 ] and in the S1 File .…”

“…Next, we assessed trends in fertility outcomes by educational level for men and women and by annual income for men. We chose to conduct analyses by subgroups based on these variables because they constitute key socioeconomic indicators and because they have been correlated with fertility [ 13 , 14 , 16 – 20 , 22 ] and related outcomes [ 5 , 21 , 23 ] in previous studies. As level of income was reported at the time of survey participation and many Japanese women work shorter hours or become homemakers after marriage and childbirth [ 9 ], we did not assess this variable for women.…”

“…On the one hand, lower income may be associated with lower fertility. This is because the likelihood of being married or being in a romantic relationship is strongly correlated with higher income among Japanese men [ 3 – 5 ] and the cost of raising children may prevent financially strained couples from having the number of children they want [ 6 – 8 ]. On the other hand, difficulties in combining full-time work with child-rearing is thought to deter some women, especially those with high education, from having children [ 6 , 7 ].…”

Antecedents of the Attitudes Toward Singlehood Among Young Adults in Malaysia, Japan, and India

“…On the other hand, in Japan, a new phenomenon "herbivorization" develops among unmarried young adults, especially men, who are impassionate in finding romantic or sexual partners of the opposite sex. There is a steady increase from 27.4 to 40.7% among females and from 40.3 to 50.8% among male 18-39-year-old singles between 1992 and 2015 (Ghaznavi et al, 2020). Other than being unemployed as well as having lower income and educational qualifications, these notorious "herbivores" are expected to eventually contribute to Japan's worsening birth rates from 127 million in 2015 to less than 90 million by 2065.…”