I think it's an interesting hypothesis, but absent any primary sources it falls into the "bullshit" category. It might be a different matter if someone were to present these "government files" that the author described. Absent any scientific backing, it's about as believable as *insert your faith here*. You can believe what you want, and I support that, but this is far from proven without appropriate documentation to reinforce it.
EXACTLY.
Plus, I've heard many a story from combat vets who sensed danger, while on patrol, running ops, etc.. Even one from my cousin who was deployed to Afghanistan. They were moving to an FOB, he told the driver to take "x" route rather than "z" route.
Few hours later when the guys that were leaving the FOB were going back to the base, they hit an IED, which killed a soldier.
So yeah, you don't really *need* to have long hair to sense danger.