A man is hiking in the countryside when he suddenly sees a toddler about to fall into an abandoned well. What will he do? Many people will instinctively run toward the toddler to save him. However, some people will simply panic, freezing in the moment of crisis. A handful of people might start to move toward the child, but then stop, because they realise that the crumbling old well could collapse under their weight. Their initial impulse to save the child competes with their desire for self-preservation.