I mean 90iq is still considered average range so to say someone with an 80iq can't comprehend things is bullshit. We have a basic understanding of morals by 5. Also they do know it's wrong. There's footage of journalists talking to rapists in Africa and they're more than aware it's bad, they don't care.
Animals don't do anything out of malicious intent as human do. If an animal hunts its because it or its pack needs to eat, if it kills otherwise its usually defense. If an animal rapes its because it needs to reproduce. Nature recognises this as bad however, animals can become traumatised because of this, female ducks have evolved to be anti r**e because of how common it is. There are absolutely some animals that do have the capacity for malicious intent however such as whales, dolphins etc.