A new study using data from South Korea finds that women who attended all-female high schools are more likely to engage in political and civic life and take on leadership roles than those who went to coeducational schools. These effects persist long after graduation. However, the study found no evidence that single-sex schooling makes women more likely to hold feminist views or reject traditional gender roles.
Across the world, women continue to be underrepresented in positions of political and organizational power. Researchers have long tried to understand what shapes this persistent gap in leadership and participation. One hypothesis is that early-life experiences—such as those in school—can play a major role in shaping ambitions and self-perceptions that influence whether people seek out leadership or civic engagement later in life.
The new study, published in the Journal of Experimental Political Science, took advantage of a rare natural experiment in South Korea to explore how school environments influence women’s later behavior in politics and leadership.
The researchers were particularly interested in whether attending an all-female high school increases women’s willingness to participate in civic life and seek out leadership roles. They also wanted to test whether such an environment changes women’s views on gender roles and stereotypes. While many have speculated that single-sex schooling might provide a more empowering context for young women, very few studies have tested this idea using methods that can establish cause-and-effect relationships.
In South Korea, however, between 1974 and 2009, students in Seoul were randomly assigned to high schools within their local districts as part of a government equalization policy. This random assignment included both single-sex and coeducational schools, which provided a unique opportunity for researchers to study the long-term effects of school environments without the confounding influence of family preferences. Because curriculum, tuition, and school standards were standardized by the government, differences in student outcomes could more confidently be linked to the type of school environment rather than other factors.
The study was co-authored by political scientist Nicholas Sambanis, who was inspired to explore the topic after choosing an all-girls middle school for his daughter. Wondering whether this decision actually influenced her development, he turned to the randomized system in South Korea to look for answers in the data.
“When I moved to the suburbs of Philadelphia to take a position at Penn in 2016, I had a choice to make regarding my daughter’s middle school. There were a couple of all-girls schools in the area that everyone said were very good, and they pitched themselves as creating well-rounded, self-assured young women who would be able to handle themselves in a workplace dominated by men,” explained Sambanis, the Kalsi Professor of Political Science and director of the Identity & Conflict Lab at Yale University.
“I enrolled my daughter in one of those schools. It was definitely less fun and I always wondered if it was the right decision so I decided to look for some data on this. Of course, it is very hard to identify the causal effect of single-sex schooling in the United States because school assignments are not random, so I collected data from Korea because school assignment there is random (ostensibly for egalitarian reasons).”
The researchers conducted a survey of over 3,400 adults in South Korea who had graduated from high schools in Seoul between 1990 and 2010. Because school assignment had been random during that period, the researchers could compare outcomes between graduates of single-sex and coeducational schools as if in an experiment. They asked participants about their past and current civic and political engagement, experiences in leadership roles, leadership attitudes, and beliefs about gender roles.
To test political participation, the researchers created an index based on self-reported involvement in activities such as voting, attending rallies, contacting public officials, signing petitions, and donating to political causes. They also separated participation into several categories, including traditional electoral activities, private activism, collective action, and political contact. All responses were converted to scales ranging from 0 to 1.
The researchers found that women who had attended all-female high schools reported higher overall political and civic engagement. Specifically, they were more likely to vote, take part in private forms of activism like donating or boycotting, and contact public officials or engage with political content online. On average, attending a single-sex school increased women’s participation score by 4.1 percentage points. These effects were statistically significant and persisted even after accounting for other background factors.
Men did not experience the same benefits. Among male graduates, there was no consistent effect of single-sex schooling on political participation, with the exception of a small increase in private activism. This suggests that single-sex schooling had a uniquely positive influence on women’s engagement with political and civic life.
When it came to leadership, the researchers examined both attitudes and behavior. They asked participants how much they agreed with statements about preferring leadership roles and feeling confident in their leadership abilities. They also asked whether respondents had ever held a leadership position in any group or organization, such as a volunteer group, community association, or professional society.
Women who had attended all-girls schools were more likely to express interest in leadership, though the increase in self-reported leadership confidence was modest—just over 2 percentage points—and only marginally statistically significant. The behavioral measure, however, showed a much stronger effect: women from single-sex schools were 7.3 percentage points more likely to have held a leadership position in a group or organization. Again, men did not show significant differences based on school type.
“The study shows that there may be a benefit for girls to be educated in an all-girl environment,” Sambanis told PsyPost. “The effect is likely due to seeing girls in leadership roles – by virtue of the school’s structure, girls will be the best students, the best athletes, the class president. This could make all girls believe that they can compete effectively and they would also be more comfortable expressing their opinions and aspirations. This effect carries over into their professional lives when they become adults and can last a lifetime.”
One unexpected result emerged when the researchers turned to gender attitudes. Despite showing higher participation and leadership rates, women who attended all-girls schools were no more likely to hold progressive views on gender roles than their peers from coeducational schools.
The researchers used two well-established measures to assess this: one for hostile sexism and one for traditional beliefs about gender roles in the household. On both scales, women overall scored lower (meaning they were less sexist and more supportive of gender equality) than men—but there was no difference between women who had attended single-sex and coeducational schools.
“My co-author, Amber Hye-Won Lee, and I were surprised not to find any effects of an all-girls education on girls’ attitudes toward gender norms,” Sambanis said. “In retrospect, this might not be surprising; for schools to such an effect, the school’s leadership and teachers probably need to consciously promote a feminist agenda, which is not the case in all-girls schools in Korea, as far as we know.”
The study has some limitations. It focuses only on people who graduated from schools in Seoul during a specific timeframe, so the findings may not generalize to all regions or countries.
“The study is limited to analyzing self-reported data obtained via surveys,” Sambanis noted. “It has the benefit of analyzing effects among people who graduated decades ago, so we can say something about the durability of effects. But we could not manipulate anything related to curriculum or other aspects of the school experience (beyond the natural experiment involving random assignment to schools). The topic is important enough to be studied more closely and prospectively in more countries using experimental methods.”
Looking forward, Sambanis said he is “considering a field experiment focused on girls’ competitiveness and a study on the effects of exposing girls to sports at an early age. But in general this line of research is not a major agenda item in my lab at the time. It was something I focused on a few years ago for personal reasons, as mentioned earlier.”
The study, “Same-Sex Schooling, Political Participation, and Gender Attitudes? Evidence from a Natural Experiment in South Korea,” was authored by Amber Hye-Yon Lee and Nicholas Sambanis.