Table 1.
Cognitive Ability Score at Enlistment in 3258 US Male Veterans According to Demographic and Army Service Characteristics
| Characteristic | No. (%) of Participantsa | Mean (SD) Cognitive Ability Score | Correlation With Cognitive Ability Scoreb |
|---|---|---|---|
| Age at enlistment, y | 0.23c | ||
| ≤18 | 408 (12.5) | 97.4 (12.9) | |
| 19–22 | 2522 (77.4) | 101.1 (15.1) | |
| ≥23 | 328 (10.1) | 106.2 (17.6)c | |
| Army income per week, US $ | 0.30c | ||
| 83–119 | 352 (10.8) | 93.2 (13.2) | |
| 120–144 | 1621 (49.8) | 98.7 (15.3) | |
| ≥145 | 1285 (39.4) | 106.3 (14.0)c | |
| Place of service | |||
| Ever in Vietnam | 1753 (53.8) | 100.0 (14.9) | |
| Other overseas | 1505 (46.2) | 101.5 (15.6) | |
| US only | 640 (19.6) | 103.6 (15.5)d | |
| Ethnic group | |||
| White | 2634 (80.8) | 103.8 (14.4) | |
| Black | 415 (12.7) | 88.1 (12.9) | |
| Other | 209 (6.4) | 93.7 (14.3)d | |
a
Percentages have been rounded and may not total 100.
b
Correlations are calculated for continuously distributed variables only.
c
P <.001 for trend.
d
P <.001 for difference.