Ask a general, wide ranging question and you get a general, wide ranging answer. However, my most vivd examples of morale boosting and effectiveness come from SAR (Search and Rescue) and in that context there were plenty of survival scenarios, both for victims and for the rescuers.

I agree with Montanero about humor - on one accident scene - a plane crash with two victims - we were informed that the victims could be flown out, but that we would have to hoof it.

From the back of the group came a small voice -"That seems only fair, they were the only ones to fly in here."

Other examples could be given of SAR humor - it is frequently a way of dealing with situations that are often rather grim.