Women on the Battlefield: Data, Science, and the Law

Anyone who hasn’t been trapped under a rock over the past few years has heard innumerable comments on the Secretary of Defense’s decision to admit women into combat career fields, and the build-up leading to this decision—the Marine Corps’ large-scale integration experiment, the Army’s adventures with females in Ranger training, etc. Most of these commentaries miss the mark in one way or another—some are little more than feelings and prejudice cloaked as professional opinion—and few begin where they should, with first principles and the law. Only with these foundations can we evaluate what the services have done in meeting the requirements laid before them. The Office of the Secretary of Defense (OSD), the services, and Special Operations Command (SOCOM) each funded research under the umbrella of this review. A SOCOM-funded survey showed that more than 80% of special operators think women are not strong enough to handle the demands of the job and 64% think women are not mentally tough enough.[1] However, there are also supporters who say that for over a decade in Iraq and Afghanistan women have shown they are physically and mentally strong enough.[2]

Given the strong opinions on both sides, are we focused on the right questions? What did the Secretary of Defense tell the services to do? And have the services adequately addressed the key points? We intend to address these questions with a focus primarily on the physical requirements.

Guiding Principles and the Law

In January 2013, Secretary of Defense Leon Panetta rescinded the Direct Combat Exclusion Rule, the policy that restricted women from serving in units with the primary mission to engage directly in ground combat.[3] To inform policy makers and mitigate possible risks to combat troops such a decision might incur, Secretary Panetta directed the military departments to review occupational standards and related policies for the affected combat specialties, an effort known as the Women in Service Review. The services were given principles to guide their review, specifically:

Validate occupational performance standards, both physical and mental, for all military occupational specialties (MOS), specifically those that remain closed to women. Eligibility for training and development within designated occupational fields should consist of qualitative and quantifiable standards reflecting the knowledge, skills, and abilities necessary for each occupation. For occupational specialties open to women, the occupational performance standards must be gender-neutral as required by P.L. 103-160, Section 542 (sic) (1993).[4]

Gender-neutral is a critical phrase in this guidance, but what does it mean? Here’s a hint: the law explicitly states standards may not be eased to ensure women can pass. But there is more to gender-neutrality than that. In fact, in 1993, Congress established a definition for gender-neutral occupational standards. Such standards:

  • shall ensure that qualification of members of the Armed Forces for, and continuance of members of the Armed Forces in, that occupational career field is evaluated on the basis of an occupational standard, without differential standards of evaluation on the basis of gender;
  • may not use any gender quota, goal, or ceiling except as specifically authorized by law; and
  • may not change an occupational performance standard for the purpose of increasing or decreasing the number of women in that occupational career field.[5]

Simply put, the standards must be the same for both men and women. And in response to concerns that physical occupational standards and tests for some career fields did not reflect actual job requirements, Congress further required the Secretaries of the military departments to develop occupational standards and tests that:

  • accurately predict performance of actual, regular, and recurring duties of a military occupation; and
  • are applied equitably to measure individual capabilities.[6]

The tests covered by these laws are the qualifying tests that are specific to occupational specialties, and not the annual physical fitness tests taken by all service members to ensure a general level of health and fitness. For example, members of the Air Force pararescue must currently take a test that includes push-ups, pull-ups, sit-ups, a run, and a fin swim, in addition to their annual Air Force fitness test (which includes a 1.5 mi run, push-ups, sit-ups, and abdominal circumference).[7]

So what will meet the legal requirements, analytically?

There are arguments asserting current standards are time-tested.[8]  However, time-tested standards and tests are, in general, no longer suitable, unless they can be shown to meet the law. How then should the review directed by the Secretary of Defense and required by public law be conducted? First, one must determine the occupationally-specific physical requirements of each combat specialty. These requirements may be different for each career type and must be determined individually. It can be logistically challenging to routinely assess performance on a full array of combat tasks. Instead, the requirements can be linked to a set of physical fitness tests that are predictive of performance. There are many research methodologies that could provide an appropriate response to the Secretary of Defense direction and the services used a few approaches. Consider the Marine Corps, for example, which compared performance of all-male teams to mixed-gender teams in simulated combat situations. [9]

What the Marine Corps study showed is that the average female marine may not be as physically capable as the average male marine. The study also showed that the bottom 25% of male marines overlap with the top 25% of female marines in terms of physical ability—yet these low-performing male marines are afforded an opportunity denied to comparable women simply because they were born with a Y chromosome. The Marine Corps is the only service to quickly publish such detailed results and ask for an exception to policy. They faced criticism and their request for an exception was ultimately denied.[10] As pointed out by many critics,[11] this approach did not address the real question—describing the physical requirements for the combat specialties under consideration—nor did it establish any criteria for describing physical qualifications for those specialties. In short, without such criteria it did not adhere to the principles or establish all of the requirements laid out in public law.  The Secretary of the Navy did not believe the Marine Corps study provided evidence for the need of an exemption to gender integration and found that the study only emphasized the importance of defining physical requirements and developing “gender-neutral, job-specific standards for each combat specialty.”[12]

Conveniently, there is a process to analyze job requirements that is widely accepted in occupational standards literature and has been used extensively by the Canadian and British militaries as well as numerous police and fire departments.[13] In this process, experts are consulted to define the critical physically demanding tasks for their profession. Controlled simulations based upon the critical physical tasks are used to link performance on the simulations to physical fitness tests. Finally, the subset of physical fitness tests and standards that are predictive of performance on task simulations can be determined. As an example, following this process, a requirement for candidates to complete seven pull-ups may be directly and analytically tied to the task of climbing a rope within a specified amount of time. The results from this process are traceable, defensible, and satisfy the legal requirements.

U.S. Army Capt. Kristen Griest participates in training at Ranger School on April 20, 2015 at Fort Benning, Ga. (U.S. Army Photo)

The Navy, Army, and Air Force have followed this process, though to different degrees. The Navy evaluated how the current selection and training procedures for SEALs are related to job performance.[14] They used experts to design representative mission scenarios and define the characteristics believed to be needed for successful mission performance. The Army used a job requirements analysis to reduce male-only jobs to the five to seven most physically demanding tasks.[15] These tasks were then translated into simple exercises such as a long jump or a grip test that could be easily performed at a recruiting station. The Air Force has conducted a full and robust study following the described process.[16] Experts scored mission tasks to identify those most critical to operational requirements. Study participants performed fitness tests to assess their physical abilities and operational simulations mimicking the most critical physical tasks. Then performance on these simulations was correlated to performance on fitness data to create a predictive subset of fitness tests.

Women pilots leaving their B-17, "Pistol Packin' Mama", at Lockbourne AAF, Ohio, during WASP training to ferry B-17 aircraft. Left to right are Frances Green, Margaret Kirchner, Ann Waldner and Blanche Osborn. (Public Domain)

What would occupationally-specific tests mean?

Will the majority of female members of the armed forces be able to pass these predictive fitness tests? Likely not. It is widely accepted that women are on average not as physically capable as men.[17] However, just as Navy Secretary Ray Mabus explained, this is not a question of averages.[18] Even the average male is ill-suited to become a Navy SEAL, and phrasing the question this way is wrong at its foundation. So what is the right question? Can a particular individual pass such a test and be a productive member of a combat specialty? If, for every female, the answer is no, then the exemptions requested by the Marine Corps may be appropriate, but they appear to lack the data to make such a claim.[19] In fact, their data indicate that some women may be physically capable of serving in these specialties.[20]

While the focus here has been on physical fitness tests, physical abilities are not the only factor in making a or assessing a combat specialist. For example, Lieutenant General Gregory Newbold, USMC (Retired), wrote an op-ed highlighting some of the mental and emotional requirements of combat and concluded that women should not be integrated into combat roles as only our young men can endure the chaos of armed combat.[21] However, he provides no data or scientific evidence to support his conclusion that women lack the mental and emotional strength and fortitude required. Importantly though, the methodologies discussed here generalize. And just as with physical requirements, any standard should be evaluated with sound research and in accordance with legal requirements. Until a test of the required mental capacity for combat exists, mentally unsuitable candidates cannot be screened regardless of gender. Once such a test exists, it can be applied to both men and women equally.

Kurdish women in a Peshmerga battalion take part in a training exercise near Sulaymaniyah, Iraq (Photograph by Mohamed Messara)

Where are we now?

After a gender-integrated pilot program in which three women successfully completed the elite Ranger training,[22] the Army permanently opened the training to all qualified soldiers.[23] Similarly, the Marines opened their Infantry Officer Course and enlisted Infantry Training Battalion.[24] A woman has yet to pass the officer course, however a third of women who attempted passed the enlisted course. Senior members of the Navy have stated that the elite Navy SEALs will be open to women who can pass their grueling six-month Basic Underwater Demolition/SEAL training.[25]

On February 2, senior officials from the Army, Navy, and Marines outlined their integration plans to the Senate Armed Services Committee, and all agreed that this is “the right path for the future.”[26] Since then Secretary of Defense Ash Carter approved the services’ implementation plans.  In his announcement he emphasized that transparent, up to date, and operationally relevant standards are paramount.[27] Claiming standards are good enough without data-driven, scientific evidence is no longer acceptable.

Of course it is not appropriate to allow every woman into combat, but neither is it appropriate to allow every man into combat roles for which they are physically unqualified. Using predictive and occupationally linked predictive fitness standards will ensure the physical preparedness of all combat troops (women included) and address the concerns of the 80% of special operators who fear female's physical limitations will degrade their combat readiness.[28]

No one knows the outcome of the integration of women into combat roles. But, as we continue with implementation, we should follow the Secretary of Defense’s guidance using data, science, and the law.

Katherine A. Batterton, Kimberly N. Hale, and Eric M. Murphy are operations research analysts for the United States Air Force. The conclusions and opinions expressed in this article are theirs alone and do not reflect the official position of the U.S. Air Force, Department of Defense, or the U.S. Government.

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Header Image: Fourth-century Greek vase showing Amazons in battle. (Getty Images)


[1] L. Baldor, “U.S. Commandos Say No to Women in Special Operations Jobs,” Military Times, 10 Dec 2015.

[2] S. Michaels, "Soldiers Blow up 5 Myths About Women in Combat," Mother Jones, 11 Jan 2016.

[3] Department of Defense, “Fact Sheet: Women in Service Review (WISR) Implementation.”

[4] Department of Defense, “Memo from the Chairmen of the Joint Chiefs of Staff to the Secretary of Defense on Women in the Service Implementation Plan,” 9 Jan 2013.

[5] National Defense Authorization Act for FY1994 (P.L. 103-160 §543, as amended by P.L. 113-66 §523)

[6] Carl Levin and Howard P. “Buck” McKeon National Defense Authorization Act for Fiscal Year 2015 (P.L. 113-291 §524)

[7] United States Air Force, “Air Force Instruction 13-219, Volume 2,” 23 Feb 2009; United States Air Force, “Air Force Instruction 36-2905,” 21 Aug 2013.

[8] L. Baldor, “U.S. Commandos Say No to Women in Special Operations Jobs,” Military Times, 10 Dec 2015.

[9] T. Bowman and L. Wagner, “Controversial Marine Corps Study On Gender Integration Published In Full,” NPR, 5 Nov 2015.

[10] A. Carter, Secretary of Defense. “Remarks on the Women-in-Service Review [Press release],” 3 Dec 2015.

[11] A. Harrington, “The Marine Corps’ Approach To Studying Women In Combat Jobs Was Flawed From The Start,” Task & Purpose, 1 Oct 2015.

[12] H. Seck, “Mabus: I'm not asking for women-in-combat exemptions,” Marine Corps Times, 15 Sept 2015.

[13] M. Singh, et al., Task Related Physical Fitness and Performance Standards for the Canadian Army, a research project submitted to Force Mobile Command Council, Ottawa, 1991; J. Bilzon, et al., “Generic Task-related Occupational Requirements for Royal Naval Personnel,” Occupational Medicine, Dec 2002 52 (8):503–510; V. Jamnik, et al., “Identification and Characterization of the Critical Physically Demanding Tasks Encountered by Correctional Officers,” Applied Physiological, Nutrition and Metabolism, Jan 2010 35:45-58.; M. Sothmann, et al., “Performance Requirements of Physically Strenuous Occupations: Validating Minimum Standards for Muscular Strength and Endurance,” Ergonomics, Feb 2004 47 (8):864-875.

[14] K. Kelly et. al., “Navy Sea, Air and Land (SEAL) and Special Warfare Combatant-craft Crewman (SWCC): Physical Standards Validation Report”.

[15] Military Performance Division, U.S. Army Research Institute of Environmental Medicine, “Development of the Occupational Physical Assessment Test (OPAT) for Combat Arms Soldiers,” Oct 2015.

[16] S. Losey, “Gender neutral standards: Opening combat jobs to women,” Air Force Times, 29 Jun 2015.

[17] P. Bishop, K. Cureton, and M. Collins, “Sex Difference in Muscular Strength in Equally-trained Men and Women,” Ergonomics, 1987 30 (4): 675-687.

[18] H. Seck, “Mabus: I'm not asking for women-in-combat exemptions,” Marine Corps Times, 15 Sept 2015.

[19] Ibid.

[20] T. Bowman and L. Wagner, “Controversial Marine Corps Study On Gender Integration Published In Full,” NPR, 5 Nov 2015.

[21] G. Newbold, “What Tempers the Steel of an Infantry Unit,” War On the Rocks, 9 Sep 2015.

[22] S. Neuman, “First Female Soldiers Graduate From Army Ranger School,” NPR, 21 Aug 2015. 

[23] M. Tan, “Army officially opens Ranger School to female soldiers,” Army Times, 2 Sep 2015.

[24] B. Jordan, “No Women Pass Marines Infantry Officer School by Experiment's End,” Military.com, 10 Apr 2015.

[25] D. Larter and M. Myers, “Navy SEALs set to open to women, top admiral says,” Navy Times, 3 Dec 2015.

[26] T. Cronk, “Officials Describe Plans to Integrate Women into Combat Roles,” DoD News, 2 Feb 2016.

[27] A. Carter, “Moving Out on Women-in-Service,” Medium, 10 Mar 2016.

[28] L. Baldor, “U.S. Commandos Say No to Women in Special Operations Jobs,” Military Times, 10 Dec 2015.