Help in identifying a Sci Fi short story and a novel set in pre-history

I may have asked one or both these questions on the old site, but if so I lost the answers. Would appreciate any help in identifying two reads:

1. Sci-Fi short story - I believe well-known and maybe a prize winner. Premise is that a very valuable mind (male) has been lost to some sort of deep madness/psychosis. He is put into an artificial primitive environment with very young children - and no other adults - despite the deadly danger to them, as he is insanely violent. The theory is that the childrens' survival-driven persistence in soliciting food/warmth/contact with the only adult available will bring him out of his madness.

2. Novel set in pre-historic times: this one is harder, as I have a less-detailed memory of it. The POV is a young girl - in one early scene, her mother gives birth and dies, though the infant lives. The father leaves the infant with the mother's body, but makes no objection when the girl picks it up and takes it with them. The infant of course still dies, and the girl grieves not so much at the death but that she had separated it from the mother, and they would now be unable to find each other in the Spirit world. It was a short novel, but in my recollection more convincingly portrayed a world in which the spirits were as real and present to the living as the concrete world around them.

I remember it as remarkable for the degree to which the author (I believe a woman) was able to create characters and inner experience without transposing a contemporary world-view.

Any help greatly appreciated.

on edit - a few words changed for clarity and addition of last descriptive paragraph on #2