Since the beginning of the Global War on Terror (GWOT) in 2001, the premium placed on Special Operations Forces (SOF) by political and military leaders has increased exponentially. With each passing year, the demand for SOF units surpasses supply, even as both the U.S. Special Operations Command and the Joint Special Operations Command expand rapidly in size and budget.

For example, the 75th Ranger Regiment added an additional line company to each of its three battalions—there are now four companies to each battalion. Both Delta Force and SEAL Team 6 added an extra assault squadron.

The Naval Health Research Center (NHRC) conducted a study titled “Predictors of Success in Basic Underwater Demolition/SEAL (BUD/S) Training: What Do We Know and Where Do We Go From Here?” Divided into two parts, the research had a dual purpose:

1) “Review the currently available literature addressing factors and characteristics that may predict the performance and success of Basic Underwater Demolition/SEAL (BUD/S) candidates.”

2) “Identify critical paths for future research, focusing on that which may yield the highest operational return in the shortest time.”

Although the study dates back to 2006, it offers some valuable insight into the traits that would make it more likely to pass BUD/S. Additionally, considering SEAL training hasn’t changed since then, it could still be used by aspiring SEALs who want to boost their chances of success. Currently, the combined SEAL pipeline has a 73 percent attrition rate.

The authors identify physical fitness, personality and psychological skills, and cerebral and neurophysiologic characteristics as the more important traits in successfully passing SEAL selection. The study concludes by recommending further research, which should “focus on advanced measurement of physical fitness, personality, psychological skills, and key cerebral and neuroendocrine markers of successful BUD/S performance using advanced medical technologies.”

However, as the authors explicitly state, their study is meant to assist in the recruiting of candidates that are more likely to pass, without compromising the existing high standards of Navy SEAL selection.

And the Navy wants candidates who are more likely to pass the whole selection process, which includes the SEAL Qualification Training course that follows after BUD/S, as the time and money investment is considerable. The NHRC study states it takes close to $350,000 to create a brand-new SEAL. Costs subsequently skyrocket when SEALs attend specialized schools.

The NHRC research authors conducted a mini-meta analysis involving 13 critically reviewed studies and numerous unpublished dissertations.

This article was originally published in April 2020. It has been edited for republication.