NAEP testing strongly suggests this, and the GSS provides evidence for it as well. The survey asked 1,195 whites if they were currently working for or ever had worked for the military or the DoD. The average IQ of those who have and those who have not, converted from Wordsum tests with the assumption that the mean white score constitutes an IQ of 100:
The leftist stereotype that dumb, destitute, and desperate people often turn to the military because they have no other options is bunk. The evidence points in the other direction, indicating that military personnel are, if anything, a cut above the civilian population they serve.
* Due to the small sample of non-whites who have served in the military, only whites are considered here.