Monday, January 05, 2026

Gender stereotypes reflect the division of labor between women and men across nations

Global data explain why cultural beliefs about the skills and personality traits of men and women differ across the world

Northwestern University

EVANSTON, Ill. --- Researchers at Northwestern University and the University of Bern in Switzerland have conducted the first cross-temporal, multinational study to compare views of gender using data collected 30 years apart.

An international study reveals that people’s beliefs about the attributes of women and men follow from the differing social roles that they typically occupy in homes and workplaces in their respective societies.

The goal driving the research was to understand the sources of stereotypes of men as assertive and ambitious and of women as the kinder and more caring gender. The study showed that these stereotypes reflect the differing social roles that are typical of women and men in homes and workplaces in nations across the world.

The researchers based their study on a Gallup public opinion poll of 22 nations from 1995, which they replicated and expanded to 40 nations in their 2023 survey. The results showed that across all nations and both time points, poll respondents reported that men are the more agentic gender, displaying qualities such ambition and competitiveness, and that women are the more communal gender, displaying qualities such as warm and caring.

The findings may seem surprising, given global trends showing the growing number of women in the paid workforce around the world. Yet, according to the researchers, a simple explanation exists.

“The persistence of the agentic male stereotype across the world reflects men’s continuous overrepresentation in the most prominent and high-status roles, such as CEOs of large corporations. In fact, although women have increasingly attained such leadership roles, these tend to be in organizations that have a more communal mission, such as executives in nonprofit and educational organizations,” said Christa Nater, the lead author of the study and a researcher at the Institute of Psychology at the University of Bern, Switzerland. Also promoting the male agency stereotype is the male dominance of a wide range of occupations demanding courage and physical strength such as firefighter, police officer and soldier.

A similar explanation accounts for how the communal stereotype of women as the kinder and more caring gender differs across nations. The researchers found that the “women are communal” stereotype was stronger in nations with greater occupational segregation of women into jobs in communal domains, such as teaching professions. In other words, stereotypes across the world reflect the roles people see women and men occupy in their societies.

“Even now, there is an easily recognized gender division of labor in the workplace and the home that accounts for the communal theme in stereotypes of women and the agentic theme in stereotypes of men,” said Alice Eagly, professor emerita of psychology at Northwestern University and coauthor of the study. “Gender stereotypes are not fiction. They represent what we observe in our daily life.”

Perhaps unsurprisingly, gender stereotypes about competence, such as intelligence and creativity, reflect the extent to which women and men obtain college degrees in their respective societies. As the proportion of women earning degrees has increased overall, people have come to believe that women and men are equally competent.

Taken together, this study suggests that gender stereotypes are a result of people’s observations of the roles that women and men typically occupy in their societies. “This means that efforts to end gender stereotypes can be effective only if women and men gain more similar positions and roles,” Nater said.

Another key finding

In nations where women had greater political power and were better represented as heads of government agencies, people ascribed more communion — but not more agency — to women than men. The likely explanation is that women tend to occupy the more communal version of roles, for example, heads of agencies pertaining to family and children, rather than financial affairs and defense.

Implications
The researchers maintained that widely shared beliefs about the traits of men and women have far-reaching consequences. Although these gender stereotypes can be helpful as shortcuts that guide thinking in everyday life, they also can foster unfair judgments of individuals who are not typical of their gender.

“Stereotypes can make people who do not fit expectations appear not just surprising, but unacceptable, leading to disapproval, for example, of a woman who excels as an aerospace engineer or a man who is a caring teacher of young children,” Nater said.

Stereotypes can harm society as well as individuals. “Gender stereotypes tend to discourage equal opportunity and disregard talent that challenges what has been typical of men and women,” Eagly said.

Policies that would support a more flexible division of labor and thereby weaken gender stereotypes include allowing parental leave for fathers and improving childcare options to enable mothers to maintain demanding careers outside the home.

The researchers pointed out the automation of many jobs that once required heavy physical labor has opened up new opportunities for women in such areas. Stereotypes are also undermined by welcoming qualified men into female-dominated roles in childcare and other caring professions. “Also helpful is government policy that challenges gender discrimination and promotes equal opportunity,” Eagly said.

The study, “Gender stereotypes across nations relate to the social positions of women and men: Evidence from cross-cultural opinion polls,” will be published by the journal Proceedings of the National Academy of Sciences (PNAS). The study is under embargo until Monday, Jan. 5 at 3 p.m. ET., after which it can be viewed online here.

DOI

10.1073/pnas.2510180122

Method of Research

Survey

Subject of Research

People

Article Title

Gender stereotypes across nations relate to the social positions of women and men: Evidence from cross-cultural opinion polls

Article Publication Date

5-Jan-2026

Microbes may hold the key to brain evolution

First-of-its-kind study offers evidence that microbes from different primate species influence physiology in ways linked to brain size and function

Northwestern University

EVANSTON, Ill. --- A groundbreaking new study reveals that changes to the gut microbiome can change the way the brain works.

Humans have the largest relative brain size of any primate, but little is known about how mammals with larger brains evolved to meet the intense energy demands required to support brain growth and maintenance.

A new study from Northwestern University provides the first empirical data showing the direct role the gut microbiome plays in shaping differences in the way the brain functions across different primate species.

“Our study shows that microbes are acting on traits that are relevant to our understanding of evolution, and particularly the evolution of human brains,” said Katie Amato, associate professor of biological anthropology and principal investigator of the study.

The study builds upon previous findings from Amato’s lab that showed the microbes of larger-brained primates, when introduced in host mice, produced more metabolic energy in the microbiome of the host — a prerequisite for larger brains, which are energetically costly to develop and function. This time, the researchers wanted to look at the brain itself to see if the microbes from different primates with different relative brain sizes would change how the brains of host mice functioned.

What they found

In a controlled lab experiment, the researchers implanted gut microbes from two large-brain primate species (human and squirrel monkey) and one small-brain primate species (macaque) into microbe-free mice.

Within eight weeks of making changes to the hosts’ microbiomes, they observed that the brains of mice with microbes from small-brain primates were indeed working differently than the brains of mice with microbes from large-brain primates.

In the mice with large-brain primate microbes, the researchers found increased expression of genes associated with energy production and synaptic plasticity, the physical process of learning in the brain. In the mice with smaller-brain primate microbes, there was less expression of these processes.

“What was super interesting is we were able to compare data we had from the brains of the host mice with data from actual macaque and human brains, and to our surprise, many of the patterns we saw in brain gene expression of the mice were the same patterns seen in the actual primates themselves,” Amato said. “In other words, we were able to make the brains of mice look like the brains of the actual primates the microbes came from.”

Another surprising discovery the researchers made was a pattern of gene expression associated with ADHD, schizophrenia, bipolar and autism in the genes of the mice with the microbes from smaller-brained primates.

While there is existing evidence showing correlations between conditions like autism and the composition of the gut microbiome, there is a lack of data showing the gut microbes contribute to these conditions.

“This study provides more evidence that microbes may causally contribute to these disorders —specifically, the gut microbiome is shaping brain function during development,” Amato said. “Based on our findings, we can speculate that if the human brain is exposed to the actions of the ‘wrong’ microbes, its development will change, and we will see symptoms of these disorders, i.e., if you don't get exposed to the ‘right’ human microbes in early life, your brain will work differently, and this may lead to symptoms of these conditions.”

Implications and next steps

Amato sees clinical implications for further exploration of the origins of some psychological disorders and for taking an evolutionary perspective on the way microbes affect brain physiology.

“It’s interesting to think about brain development in species and individuals and investigating whether we can look at cross-sectional, cross-species differences in patterns and discover rules for the way microbes are interacting with the brain, and whether the rules can be translated into development as well.

“Primate gut microbiota induce evolutionarily salient changes in mouse neurodevelopment” will be published by the Proceedings of the National Academy of Sciences of the United States of America. The embargo will lift on Monday, Jan. 5 at 3 p.m. E.T. After it publishes, the study can be read online here.

Journal

Proceedings of the National Academy of Sciences

DOI

10.1073/pnas.2426232122