Demographic data from individual studies (n=21)
| Author (year) (reference) | Geographical setting | SOF population | Sample size | Age (years)* | Sex | Military experience (years)* | Rank |
| Pirson and Pirlot (1990)18 | Belgium | ParaCommando Regiment | 1880 | 18–27 | Male only | Trainees | Trainees |
| Linenger et al (1993)19 | USA | NSW SEAL trainees | – | 18–31 | Male only | Trainees | Trainees |
| Shwayhat et al (1994)20 | USA | NSW SEAL trainees | 224 | 22.3±2.6 | Male only | Trainees | Trainees |
| Kragh et al (1996)22 | USA | USASOC Army Rangers | 556 | 24 (18–43) | –† | 4.4 | E-5, PTE-LTCOL |
| Miser et al (1995)21 | USA | USASOC Army Rangers | 471 | 22.7±4.2 | –† | 3.1±2.9 | E-4 (mean) |
| Ensign et al (2000)24 | USA | NSW SWCC | 154 | 32.0±5.9 | –† | 12.0±5.5 | – |
| Schumacher et al (2000)23 | USA | USASOC Army Rangers | – | – | –† | – | – |
| Kotwal et al (2004)25 | USA | USASOC Army Rangers | 634 | 18–48 | –† | – | PTE-COL |
| Hughes and Weinrauch (2008)26 | Australia | ADF 4RAR | 254 | – | – | – | – |
| Lynch and Pallis (2008)37 | USA | USASOC 5th SFG | – | – | –† | – | – |
| Hollingsworth (2009)28 | USA | MARSOC 1st MRB | 87 | 26.8±4.3 | –† | 7.6±3.9 | – |
| Reynolds et al (2009)‡27 | USA | – | 162 | 30.5±6.0 | –† | – | – |
| Abt et al (2014)29 | USA | USASOC 3rd SFG | 106 | 31.7±5.3 | –† | 11.0±5.5 | – |
| Teyhen et al (2015)30 | USA | USASOC Army Rangers | 188 | 23.3±3.7 | Male only | 1–10 | – |
| Lovalekar et al (2016)31 | USA | NSW SEAL | 210 | 28.1±6.0 | Male only | – | – |
| Heebner et al (2017)34 | USA | USASOC SOF | 95 | 32.7±5.1 | –† | – | – |
| Lovalekar et al (2017)32 | USA | – | 101 | 28.5±5.6 | Male only | – | – |
| Lovalekar et al (2017)33 | USA | NSW SEAL, SWCC, SQT, CQT | 920 | – | –† | – | – |
| Lovalekar et al (2018)35 | USA | AFSOC 24th SOW | 130 | 29.1±5.2 | –† | – | – |
| Teyhen et al (2018)*36 | USA | USASOC Army Rangers | 207 | – | –† | – | – |
| Dijksma et al (2020)17 | Netherlands | RNLMC Trainees | 482 | 20.6±2.3 | Male only | Trainees | Trainees |
(–) data not reported.
*Values are presented as reported by individual studies using either range, mean with SD, or a mean with a range in brackets.
†Special Operations Forces positions only open to females in the USA in January 2016.38
‡Data extracted on Special Operations Forces population cohort.
ADF, Australian Defence Force; AFSOC, Airforce Special Operations Command; COL, Colonel; CQT, Crewman Qualification Training; LTCOL, Lieutenant Colonel; MARSOC, Marine Special Operations Command; MRB, Marine Raider Battalion; NSW, Naval Special Warfare; PTE, Private; 4RAR, 4th Royal Australian Regiment; RNLMC, Royal Netherlands Marine Corps; SEAL, Sea Air and Land; SFG, Special Forces Group; SOF, Special Operations Forces; SOW, Special Operations Wing; SQT, SEAL Qualification Training; SWCC, Special Warfare Combatant Crewman; USASOC, United States Army Special Operations Command.