[Zuider]

This is well known. People tend to freeze when confronted with a novel situation. That is why there are fire drills, and why soldiers are drilled until obeying orders is reflexive.

When people freeze like this, they are not just idly goofing about, but are in a state of high tension and indecision, looking to see what everybody else is doing, or for someone who appears to know what must be done to take the initiative.