Rise of the relationship herbivore - Japanese increasingly single, disinterested in dates Finances and education predict relationship status Research news

November 10, 2020

In Japan, the proportion of the population who are single has increased dramatically in the past three decades. In 2015, 1 in 4 women and 1 in 3 men in their 30s were single, and half of the singles say they are not interested in heterosexual relationships. Public health experts at the University of Tokyo found that those who are disinterested in relationships are more likely to have lower incomes and less education than their romantically minded peers, potentially pointing towards socioeconomic factors behind the stagnation of the Japanese dating market.

The Japanese media has dubbed the much-discussed increase in virginity and a purported decline in interest in dating and sex as symptoms of the “herbivore-ization” of younger generations. In popular culture, adults who are unmarried and seemingly disinterested in finding romantic or sexual partners are “herbivores” and those who are actively pursuing romantic partners are “carnivores.”

“This herbivore phenomenon, both its definition and even does it really exist, has been hotly debated for a decade in Japan, but nationally representative data have been lacking,” said Dr. Peter Ueda, an expert in epidemiology and last author of the research published in the journal PLOS ONE.

Millions more singles in Japan

The new analysis used data collected by the National Fertility Survey of Japan, a questionnaire designed and implemented approximately every five years between 1987 and 2015 by the Japanese National Institute of Population and Social Security Research.

Japan does not yet have marriage equality for same-sex couples and the survey language explicitly asked only about heterosexual relationships. The research team says any nonheterosexual survey respondents would be hidden in the data, likely responding as single and not interested in a relationship, regardless of how they might prefer to describe themselves.

By 2015, there were 2.2 million more single women and 1.7 million more single men in Japan aged 18 to 39 compared to 1992. In 1992, 27.4% of women and 40.4% of men in Japan aged 18 to 39 were single. By 2015, 40.7% of women and 50.8% of men of the same age range were single.

The research team speculates that the higher numbers of single men might be due to women, on average, dating men who are older than themselves, such that many of their male partners were older than 39 years and thus outside of the investigated age range. Other contributing factors could be that Japan’s total population of 18- to 39-year-olds includes more men, men being more likely to date more than one partner, or differences in how men and women report their own relationship status.

Singles more common in Japan than Britain or America

Separate surveys conducted between 2010 and 2018 in Britain, the U.S. and Japan reveal that although similar proportions of women are single at ages 18 to 24, substantially more Japanese women stay single as they age. The proportion of women aged 18 to 24 and the proportion of women aged 35 to 39 who are currently single were 65.6% and 24.4% in Japan, 41.5% and 14.0% in Britain, and 62.6% and 16.6% in the U.S.

The numbers of single men are higher in Japan than in Britain or the U.S., but less dramatically different than women. British data come from the Natsal-3 survey from 2010 to 2012. American data come from the General Social Survey from 2012 to 2018.

Disinterested in a relationship now, but still hoping for marriage someday

The steady increase in single people since 1992 in Japan is driven mostly by steady decreases in marriages, while the number of people who describe themselves as “in a relationship” has remained stable.

“After age 30, either you’re married or you’re single. Very few people in the older age groups are unmarried and in a relationship. It could be speculated that promoting marriage as the most socially acceptable form of relationship between adults has built a barrier to forming romantic relationships in Japan,” said Ueda.

In the 2015 survey, single people were asked follow-up questions about whether they were interested or not interested in finding a relationship. Over half of all single people who said they were disinterested in relationships also said they still hoped to get married eventually, 62.9% of women and 65.7% of men.

Younger Japanese were more likely to say they were disinterested in relationships. About one-third of women (37.4%) and men (36.6%) aged 18 to 24 described themselves as single and not interested in a relationship. Only 1 in 7 (14.4%) women and 1 in 5 men (19.5%) aged 30 to 34 described themselves as single and disinterested.

Employment, education increase eligibility for marriage

“Among men, lower income was strongly associated with being single, although this does not necessarily represent causality. If we transferred a million dollars into their bank account right now, it is not clear if single people would increase their interest in changing their relationship status. However, it would not be too far-fetched to expect that lower income and precarious employment constitute disadvantages in the Japanese dating market,” said Ueda.

Regardless of age, married men were most likely to have regular employment and had the highest incomes. While 32.2% of married men had an annual income of at least 5 million Japanese yen (about US$48,000), this proportion was 8.4%, 7.1% and 3.9% among those in a relationship, single with interest and single without interest, respectively.

“The herbivore phenomenon may be partly socioeconomic adversity. If government policies directly addressed the situation of low-income, low-education populations, I think some people with a lack of job security or financial resources may have new interest in dating,” said Dr. Haruka Sakamoto, an expert in public health and co-author of the research publication.

In Europe and the U.S., marriage is often associated with higher incomes and education among both women and men, but it is not known how these factors influence single people's interest in romantic relationships.

Economic effects of the pandemic may further decrease young adults’ interest in finding romance.

“If low socioeconomic status is contributing to this decrease in dating in Japan, we can guess that COVID-19 economic stress could lead to even fewer romantic pursuits in the country,” said Ueda.


Cyrus Ghaznavi, Haruka Sakamoto, Shuhei Nomura, Anna Kubota, Daisuke Yoneoka, Kenji Shibuya, Peter Ueda, "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," PLOS ONE: November 9, 2020, doi:10.1371/journal.pone.0241571.
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