This sounds a lot like sociopathy. I've read that sociopaths are not scared like normal people are in frightening situations. Maybe dysfunction of the amygdala is part of that too.
I've read that sociopathy may be related to a dysfunction of the brain's ability to sympathize with others. Perhaps it's a combination of the two.
Who knows, it might have conferred a survival advantage in our distant past--bands of nomadic hominids might have had to kill and even eat each other at times.
Sociopathy is more likely related to mate competition than cannibalism, which is almost never practised for food, but rather for its ritual significance. Cannibalism was fairly widely and routinely practised in pre-political states--to the extent that in Polynesia there is a prion disease that appears to have evolved with cannibalism as a vector--but even amongst peoples where it was practised, in times of starvation people would mostly starve rather than eat each other.
A number of early European explorers (including Champlain, if memory serves) describe ritual cannibalism--generally the consumption of prisoners, who were first tortured to death in that holistic and natural way First Peoples had--but also describe people starving to death in times of want without resorting to it.
In the case of this woman, her amygdalae have been damaged by Urbach-Wieth disease, which according to the article is extremely rare.
That said, it is likely that there is a wide distribution of various types of emotional response in the populace due to variations in neurological capability.
>"I've read that sociopathy may be related to a dysfunction of the brain's ability to sympathize with others."
Perhaps they fail to empathize or sympathize with their "future self", which is who they view as the recipient of whatever it is they should be scared of currently.
I don't think failure to sympathize with 'future self' is limited to sociopaths. I could give some common examples but I was up until 7am so I'm a little fuzzy at the moment.
That's a very interesting thought. If that hominid was indeed superior, there would be more of those genetic traits still around, but it's fear which is a double edged sword - it makes some wiser, and some not-so-wise.
Or maybe it's our turn (the homo sapiens who have fear) turn to die out, letting more fearless ones take place. Although, this sounds more of a fictional novel waiting to be written.
