Not everyone who's had traumatic experiences has PTSD.
The scientists have a theory, and it has to do with the root causes of PTSD, previously undocumented. As compared with the resilient Danish soldiers, all those who developed PTSD were much more likely to have suffered emotional problems and traumatic events prior to deployment. In fact, the onset of PTSD was not predicted by traumatic war experiences but rather by childhood experiences of violence, especially punishment severe enough to cause bruises, cuts, burns and broken bones. PTSD sufferers were also more likely to have witnessed family violence and to have experienced physical attacks, stalking or death threats by a spouse. They also more often had past experiences that they could not, or would not, talk about.
This thread is for asking any questions that might seem obvious, tangential, silly or what-have-you. Don't be shy, everyone has holes in their knowledge, though the fewer and the smaller we can make them, the better.
Please be respectful of other people's admitting ignorance and don't mock them for it, as they're doing a noble thing.
To any future monthly posters of SQ threads, please remember to add the "stupid_questions" tag.