Many people have cited the infamous predator scene as proof that the penguins have no emotions.
In fact, the predator scene shows that the penguins are no different than humans, many of whom stand by and watch as other humans are fatally or serisouly injured in car crashes and are even subjected to brutal acts of violence.
I agree with the OP, and for those who say Penguins are emotionless.
Isn't fear an emotion? The Penguin Chick was running like a lunatic to flee away from the Bird. For those penguins who just stood there, maybe they were scared stiff? Ever notice that Humans have to keep perfectly still to defend from a predator? Like for example, survival guides usually tell us do not run from a Animal, but keep perfectly still. I think that what the Penguins were executing while the baby chick was being attacked. The Bird had one hell of a beak, I don't think a couple of penguins would sacrifice themselves for a battle they can't win.
Assuming we're talking about the scene with the bird... um... the non-penguin bird attacking the babies, we really only saw part of it, which goes back to the thread about how it would be nice to have some more substantial information in the narration. Are these predators ever successful? Is this just a learning experience for the babies? Do the adult penguins ever interfere?
It seemed to me that the adult penguins are simply too big to be threatened by that predator. They could probably have intervened, although it might not have been necessary.
It seemed as if the predator wasn't successful except perhaps at teaching the babies two things: - there are creatures that will try to kill you - when you see one, you should quickly seek shelter among the adults
Before condemning the adult penquins as idle (and unemotional) bystanders to a marauding petrel attacking their chicks, first consider the relative strengths of the two birds. Petrel: Can fly and is very mobil on the ground. Penguin: Can't fly and shuffles at probably a third of the petrel's footspeed. So exactly how is an adult penguin supposed to defend against a petrel that can drop from the sky and move rapidly against chicks that have no knowledge of what a predator is? If the arena were the ocean, it would be no contest. When chicks were within a few feet of adult penguins, I observed the adults actively defending (honking & flapping fins) against the petrel when it attacked chicks. Another point to consider is that the adult penguins are almost always in a fasting mode when in the rookery and conserving as much energy as possible to just maintain their body temperature and feed their chicks. Given their very real risk of starvation, fruitlessly "running" after petrels could risk the adults' lives and future generations of penguins. Re/ the petrel's attack in the movie, I remember seeing the petrel make 3 attacks. The first 2 were unsuccessful, and the 3rd was unresolved leaving doubt as to whether the chick evaded the petrel. It left me curious as to what happened to the chick.
I have no idea how penguins experience emotions. Certainly not like human beings simply because they are not human beings! What does expect to see the people who says penguins are emotionless? To watch a penguin crying like Ingrid Bergman in 'Casablanca' or what? pfft! People tends to "humanize" animals a bit too much. Remember that penguins are not even mammals but birds. How many birds shows emotions as dogs or cats does? What about fishes or reptiles? They surely feel something but they are not like us, that's why is so fascinating to watch their behaviour.