LOL! Of course the traditional ameriKan ways is that only the fizicly and mentally fittest were allowed into the great murder-suicide machine. Moloch demands only the best and brightest young men!
The less intelligent are, on average, naturally more likely to die in war. However, in the case of the War of Northern Aggression, a lot of the more intelligent people of the South died than did the intelligent people of the North. College professors and such fought and died for the South, whereas in the North, that class avoided battle, and often military service altogether.
Confederate General Wade Hampton -- later governor of South Carolina -- said that the War for Southern Independence was a noble struggle for liberty and self-determination that cost the South "her best blood and all her treasure."
Southerners were fighting for their independence. Northerners didn't have much interest. My greatgrandfather's mother paid $300 for a substitute which might have saved his life.