Fight or flight, the natural reactions to fear. Though, people don't mention one, freeze. People like to ignore that possibility because it tends to put them in danger. Unfortunately for them, it is real, it is dangerous, and it is terrifying if you happen to be the one experiencing it. -- Anon Guest
Most Humans can be relied upon to act quickly in an emergency. Most of them. Their presence in any place of inherent hazard is reassuring to anyone in field of view. There is a Human, they think, even if the worst happens, all will be well. For the most part, it is a reasonable assumption.
They also think that Humans only have two reactions to that which they fear - the typical 'fight or flight' that has had so many stories spring up around it. What they did not know, until the latter half of the 423rd Century, was that there was a third option.
There was chaos all around him. People were hurt. People were crying out in pain. Things were on fire. Things were collapsing. Despite all this, Len was frozen in place. He could barely breathe, and he certainly couldn't move. His brain was full of static and nothing seemed to be able to shake him out of it. He wanted to shake out of it, but there was... a sort of wall. The want didn't reach his muscles. It certainly didn't reach his brain, which was screaming, What are you doing just standing there? Move! Do something! Yet the all important knowledge of what to do just never arrived.