Can Integration Change Gender Attitudes?


Can integration of men and women change gender attitudes even in a traditionally male-dominated environment? This research carried out a randomized experiment in the Norwegian military, to study the effects of mixed-gender training squads on male squad members. This casts some light on what social psychologists call the “contact hypothesis”, which predicts that exposure to members of a minority group can change the biases and beliefs of the dominant group.

We carried out the experiment at the boot camp stage of training, lasting eight weeks. We randomized female recruits to some squads but not others during this time. The experiment provided intensive exposure of men to women during these eight weeks: there are typically six people in each squad, who train as a team during the day and also live together in the same room. 

To track changes in attitudes, we conducted a baseline survey prior to the start of boot camp, conducted another survey near the completion of boot camp, and also have access to a survey six months into military service. The surveys asked a variety of questions, including beliefs about the performance of mixed-gender teams, gender roles and the division of household chores, and self-perceptions of feminine personality traits.

We find that, when men live and work closely with women for eight weeks, they have more egalitarian attitudes by the end of boot camp compared to those in men-only squads. Immediately after boot camp, they are also more likely to choose military roles with a higher fraction of women. The effects are sizeable but fade over time: in the six-month follow-up survey, gender attitudes of men in the mixed-gender squads had converged to those of the control group.

Main article

Many occupations in rich countries remain segregated by gender, but perhaps better integration could change gender attitudes. This column reports on an experiment which randomly assigned female recruits to training squads in the Norwegian military. We find that men who live and work closely with women for eight weeks develop more egalitarian gender attitudes and choose military roles with more women. The effects are sizeable but fade over time, suggesting that durable change may require durable intervention.

The research described here asks whether integration can change gender attitudes even in a traditionally male-dominated environment. One reason to ask this question is that occupational gender segregation remains high, even though women make up nearly half the labor force in most rich countries (Blau et al. 2013). This pattern may reflect preferences that differ between men and women, such as a desire for jobs with more flexibility (Goldin 2014). But it may also be the result of discrimination, stereotypes, and belief distortions (Bordalo et al. 2016).

To the extent that gender segregation influences attitudes and behavior, the pattern may be self-reinforcing. Segregated groups may develop negative attitudes and stereotypes that lead to further segregation. On a more positive note, the pattern may change quickly to a new and persistent “equilibrium” outcome, if initial changes in the gender balance influence future segregation and attitudes.

A possible mechanism for change is what psychologists label the contact hypothesis, which predicts that exposure to members of a minority group can change the biases and beliefs of the dominant group. The idea is that mixing groups will break down stereotypes and encourage understanding, especially if the two groups interact at a personal level and are given equal status and common goals (Allport 1954).

Understanding the causal links between segregation and attitudes is difficult. Segregation may affect attitudes, attitudes may affect segregation, and there are many other factors that may affect both segregation and attitudes. Given this complexity, there has been relatively little firm evidence to date.

The research we summarize here uses an experiment to study the issue. We randomly assigned women to mixed-gender teams in the Norwegian Army, a traditionally male-dominated environment in which women make up about 15% of the workforce. The experimental design enables us to examine whether integration changes attitudes about mixed-gender productivity, gender roles, and gender identity (Dahl, Kotsadam, and Rooth 2021). We can also study whether integration changes the willingness of men to work in military occupations with more women in them.  Along both of these dimensions, we find positive short-run effects, but these fade out over time, after the intense exposure has ended.

The experiment and data

We conducted the field experiment by collaborating closely with the North Brigade of the Norwegian military and the Norwegian Defense Research Establishment. We randomly assigned female army recruits to some squads but not others, during boot camp in 2014. Importantly, our experiment did not introduce the use of mixed-gender squads, as male and female recruits have been integrated into squads in the North Brigade since 2010.

“we can examine whether integration changes attitudes about mixed-gender productivity, gender roles, and gender identity”

Boot camp is an intense period of training and lasts for eight weeks. The objective is to prepare soldiers physically and mentally for military service. Recruits are grouped into squads, typically composed of six soldiers. These squads train together as a team and live in the same room. Since recruits are not allowed to leave base during boot camp, they spend most of their daytime and night-time hours together.

In the field experiment some men trained with female recruits at boot camp, while others were in men-only squads. The “treated” men live and work closely with women in their squad, usually two women and four men. The “untreated” male recruits, in the control group, have only other men in their squad, usually six in total.

Before the soldiers fly to northern Norway for their training, they meet up at a military camp outside Oslo to go through final screening and checks. At this point, the soldiers do not know each other, nor do they know who they will share teams and rooms with. This is when we conducted our baseline survey of gender attitudes, to find out what these were before training began.

To develop the battery of questions, we consulted with the Norwegian Defense Research Establishment. We included questions on demographics, personality traits, leadership potential, and military service. Three questions captured attitudes on gender equality. We first ask recruits if they think mixed-gender teams underperform all-male teams in this military setting. Second, we ask about gender roles and the division of household chores. Third, we ask about an individual’s self-perception of femininity. In addition, the survey includes questions about self-assessed military preparedness and satisfaction with the period of service. We conducted follow-up surveys in northern Norway at the end of the boot camp and again at six months after boot camp.

In addition to the survey data, we have a set of outcomes collected by the military. These include promotion outcomes after the end of boot camp, occupations assigned after boot camp, and service evaluations conducted near the end of service. By linking this with data from Statistics Norway, we tracked the education and occupational choices made after the end of service. In particular, we investigate whether those men exposed to the “treatment” of mixed-gender boot camp squads were differently influenced in their later choices of field of study or employment by the fraction of women in those fields.

Short-run effects on attitudes and occupations

We find that, when men live and work closely with women for eight weeks, they develop more egalitarian attitudes in the short run. Men who have women randomly assigned to their squads are 14 percentage points more likely to think mixed-gender teams perform as well or better than same-gender teams. There is an 8 percentage point increase in men who think household work should be shared equally and a 14 percentage point increase in men who do not completely disavow feminine traits. Depending on the outcome, exposure to a mixed-gender squad reduces the gap in mean attitudes between men and women by between 31 and 46 percent.

“when men live and work closely with women for eight weeks, they develop more egalitarian attitudes in the short run”

Immediately after boot camp, men exposed to mixed-gender squads are more likely to choose, and be assigned to, military occupations which have a higher fraction of women. For treated men, there is a 22 percent increase in the fraction of women in their military occupation, relative to the control group. We interpret this finding as largely reflecting the altered preferences of recruits, since the military tries to match soldiers with their desired roles in order to maintain high motivation.

Medium-run effects

We next ask whether short-run changes in gender attitudes and occupation choices persist over time. Using a six-month follow-up survey, we find that treated men’s gender attitudes converge to those of the controls, eliminating the short-run differences observed at the end of boot camp. Consistent with finding no long-run gap in gender attitudes, there is no evidence that treatment influences future education or civilian occupation choices. Using linked administrative register data, we find that treated individuals are not more likely to enroll in a field of study, work in an occupation, or be employed in an establishment with a higher fraction of women in the years following military service.

As background, note that squad assignments made during boot camp do not continue into later service. After boot camp ends, the soldiers are assigned to new squads whose members serve in a variety of military occupations. Given this reshuffling, the extent of exposure (in terms of the number of women) and its intensity (in team-building and spending time together) are typically lower after boot camp. This means that our experiment studies a temporary intervention, rather than a more lasting one.

Does integration influence satisfaction or performance?

Besides studying gender attitudes and occupational choices, we also examine how exposure to women during boot camp altered the performance of male recruits and their military experience. In both the short run (during bootcamp) and long run (subsequent military assignment) we find no evidence of any negative effects along these dimensions. Men exposed to mixed-gender boot camp squads feel equally qualified for the military, and are as satisfied with their service, in both the short and longer run.

Looking at more objective outcomes, treated men are equally likely to be promoted at the end of boot camp, and have similar scores on performance evaluations assigned at the end of service. These findings are especially relevant for countries considering further integration of women into the military. Many policymakers have worried that allowing women to serve in the military would ruin its esprit de corps, but this does not appear to be the case.


The positive short-run findings indicate that intensive exposure, even over a short time, can change attitudes. This is in line with contact theory. Previous research has found similar effects of other types of exposure, in particular across caste, religion, or ethnic groups (Carrell, Hoekstra and West 2015, Finseraas et al. 2019, Lowe, 2020, Mousa, 2020, Scacco and Warren, 2018) but also with respect to income (Rao, 2019) and gender (Finseraas et al., 2016). However, little is known about the persistence of these effects.

“Many policymakers have worried that allowing women to serve in the military would ruin its esprit de corps, but this does not appear to be the case”

While we find no evidence of longer-run effects in this experiment, perhaps other forms of integration could change attitudes and choices even in the longer run. The sharp contrast between our short-run and long-run results suggests that, to maintain changed attitudes and behavior, exposure likely needs to be maintained for a longer period. Our intervention, while intense during boot camp, was relatively short compared to the overall military experience. And our setting is an extreme example of a male-dominated environment, where attitudes may be the most difficult to change permanently without continuing exposure. An important question for future research is whether the effects would persist under alternative interventions. Durable change may require durable intervention.

This article summarizes “Does Integration Change Gender Attitudes? The Effect of Randomly Assigning Women to Traditionally Male Teams”, published in the Quarterly Journal of Economics in May 2021.

Gordon B. Dahl is at the Department of Economics, UC San Diego, Andreas Kotsadam is at the Ragnar Frisch Centre for Economic Research in Oslo, and Dan-Olof Rooth is at the Swedish Institute for Social Research, Stockholm University.

Further reading

Allport, G. W. (1954). The Nature of Prejudice. Reading: Addison-Wesley.

Blau, F., Brummund, P. and Liu, A. Y.-H. (2013). Trends in occupational segregation by gender 1970-2009: adjusting for the impact of changes in the occupational coding system. Demography 50(2), 471-492.

Bordalo, P., Coffman, K., Gennaioli, N. and Shleifer, A. (2016). Stereotypes. Quarterly Journal of Economics 131(4), 1753-1794.

Carrell, S. E., Hoekstra, M. and West, J. E. (2015). The impact of intergroup contact on racial attitudes and revealed preferences. National Bureau of Economic Research working paper no. 20940.

Dahl, G. B., Kotsadam, A. and Rooth, D.-O. (2021). Does integration change gender attitudes? The effect of randomly assigning women to traditionally male teams. Quarterly Journal of Economics, 136(2), 987-1030.

Finseraas, H., Hanson, T., Johnsen, Å. A.,  Kotsadam, A. and Torsvik, G. (2019). Trust, ethnic diversity, and personal contact: a field experiment. Journal of Public Economics 173, 72–84.

Finseraas, H., Johnsen, Å. A., Kotsadam, A. and Torsvik, G. (2016). Exposure to female colleagues breaks the glass ceiling: evidence from a combined vignette and field experiment. European Economic Review 90, 363–374.

Goldin, C. (2014). A grand gender convergence: its last chapter. American Economic Review 104(4), 1091-1119.

Lowe, M. (2020). Types of contact: a field experiment on collaborative and adversarial caste integration. CESifo working paper no. 8089.

Mousa, S. (2020). Building social cohesion between Christians and Muslims through soccer in post-ISIS Iraq. Science 369 (6505), 866–870.

Rao, G. (2019). Familiarity does not breed contempt: Generosity, discrimination, and diversity in Delhi schools. American Economic Review 109 (3), 774–809.

Scacco, A. and Warren, S. S. (2018). Can social contact reduce prejudice and discrimination? Evidence from a field experiment in Nigeria. American Political Science Review, 112 (3), 654–677.