In an experiment by the U.S. Marine Corps on the integration of women into combat units, mixed-gender units didn’t perform as well as all-male units.

With a January 1 deadline to admit women to combat roles or seek an exception for some jobs, the Marines created a 400-person combat unit, including 100 women. The unit underwent a year-long deployment, training for combat and performing in simulated combat. The results showed all-male units performed better.

Some examples from the study, as reported by NPR:

Speed: All-male squads, regardless of infantry MOS (Military Occupational Specialty), were faster than the gender-integrated squads in each tactical movement. The differences were more pronounced in infantry crew-served weapons specialties that carried the assault load plus the additional weight of crew-served weapons and ammunition.

Lethality: All-male 0311 (rifleman) infantry squads had better accuracy compared to gender-integrated squads. There was a notable difference between genders for every individual weapons system (i.e. M4, M27, and M203) within the 0311 squads, except for the probability of hit and near miss with the M4.

Obstacles and casualties: All-male squads, teams and crews and gender-integrated squads, teams, and crews had a noticeable difference in their performance of the basic combat tasks of negotiating obstacles and evacuating casualties. For example, when negotiating the wall obstacle, male Marines threw their packs to the top of the wall, whereas female Marines required regular assistance in getting their packs to the top. During casualty evacuation assessments, there were notable differences in execution times between all-male and gender-integrated groups, except in the case where teams conducted a casualty evacuation as a one-Marine fireman's carry of another (in which case it was most often a male Marine who “evacuated” the casualty).

It was pointed out, according to Svati Kirsten Narula of Quartz, that the male Marines in the trial were mostly combat veterans, whereas the women, by definition, had not seen combat and were mostly recent graduates of infantry school or had come from non-combat roles.

The Marines did not indicate in the report whether they would seek exemptions from the women-in-combat mandate.

-Steve Straehley

To Learn More:

The Marines Tested Totally Male Squads Against Mixed-Gender One (by Svati Kirsten Narula, Quartz)

Marine Corps Force Integration Plan—Summary

Marines Clash about Women in Combat (by Noel Brinkerhoff, AllGov)

139 Female Soldiers Have Died in Iraq and Afghanistan (by David Wallechinsky and Noel Brinkerhoff, AllGov)