How are Akkis (fiends/ogres) immune to death-feedback? In Shinsekai Yori (From the New World), humans with Cantus powers are prevented from attacking each other by:


Mental Restraints: It prevents humans from intentionally attacking other humans.
Death Feedback: If a human kills another human, the attacker dies as well.


This is what keeps humans with Cantus powers from destroying each other.



Akkis (translated as: fiends (UTW subs), ogres (Crunchyroll)) are mentally unstable and are able to break the mental restraints. So they have no problem attacking other humans. But what about the death feedback?

How are they immune to death feedback? What makes them different from normal humans?
The Death Feedback is part genetic and part conditioned. From episode 4, they mention that the human genome was modified and that the Death Feedback works by the subconscious becoming aware of an attempt to harm another human and it uses their power to stop liver functions and parathyroid glands. This is further reinforced by education, conditioning and hypnosis. I think in episode 12 Tomiko speculates that it could be possible to circumvent the Death Feedback if the user was on some kind of stimulants or somehow didn't recognize their targets as human.

This is possibly why the monster rats can raise a human child as one of their own species, and the child will grow up not recognizing humans as his/her own species so the child would be able to kill humans (but not the rats). It's also mentioned that the ogres are genetic mutations, possibly without the Death Feedback genome, but that wouldn't account for the rats stealing human infants since there's no guarantee that the infants have the mutation.