The Marine Corps recently finished a nine-month long experiment at both Camp Lejeune, North Carolina, and Twentynine Palms, California, to assess how female service members perform in combat:

It found that all-male squads, teams and crews demonstrated better performance on 93 of 134 tasks evaluated (69 percent) than units with women in them. Units comprising all men also were faster than units with women while completing tactical movements in combat situations, especially in units with large “crew-served” weapons like heavy machine guns and mortars, the study found.

Infantry squads comprising men only also had better accuracy than squads with women in them, with “a notable difference between genders for every individual weapons system” used by infantry rifleman units. They include the M4 carbine, the M27 infantry automatic rifle (IAR) and the M203, a single-shot grenade launcher mounted to rifles, the study found.

The research also found that male Marines who have not received infantry training were still more accurate using firearms than women who have. And in removing wounded troops from the battlefield, there “were notable differences in execution times between all-male and gender-integrated groups,” with the exception being when a single person — ”most often a male Marine” — carried someone away, the study found.