ES, as an institution, the military does tend towards people with similar personalities. The ones who don't fit in either get booted, don't advance, or serve their initial enlistment and get out. Are we clones? No. However, due to similar training and experiences, we can take a group of 150 soldiers and have them functioning as a cohesive unit in a fairly short amount of time.

The lack of a sense of humor about events is one of the prime indicators of combat stress. One soldier who I have served a long time with is currently in rehab for wounds recieved from an IED, and I knew Ken was going to be okay when he was joking about the wounds in his email.