I spotted a story about a cat that alerted its owners to a house fire and saved them from harm. It sounds good in theory but are cats really that noble? My wildest guess would be no. But we have to examine cat motivation before we can render a final decision.
The heroic cat had some serious motivation in the fire: He had little desire to become a crispy critter. The short list of options available to Tabby included alerting the owners or Kitty flambé as a main course.
Cats look after themselves first and foremost. The cat in question was probably unable to work the doorknob, or his owners would have been a casual afterthought for him. Cat owners fulfill one primary function for cats: They either provide food or become food if said owner is a crazy person who dies alone with 53 cats in the house. Mainly because cats are not good with can openers, and they can’t order in some take-out.
Cats are pretty good actors. It appears that they can mimic real affection for people. It is actually a pretty clever trick, but not unique to cats. My goldfish can do the same thing when they’re hungry.
Cats follow their natural hunting instincts in most situations. They will likely annihilate every bird within three miles of home, but mice are another issue. It turns out that they are too lazy to hate meeses to pieces. They like low hanging fruit such as flightless baby birds better than furtive and speedy rodents.
So you can rule out useful purposes for cats under normal conditions. Every cat in the world should sing the praises of the cat that saved the family from the fire. It was a public relations dream for cats. All the rest of us have to do is completely suspend reality and believe that the cat had pushed the family’s welfare ahead of its own. For me, that is a tall order.