Barren walls, neat small hordes of interesting things on bookshelves and in drawers, all my furniture is either beech wood or its grey or black. I was a bit more of an interest hoarder when I was younger, but then I lived with a trinket collector and I developed an aversion to too much stuff so now I get rid of stuff I dont use.
I assume this is here because maybe you feel he is displaying autistic traits? Firstly: im not a psychologist. From reading 50s and 60s sci fi, authors tend to not seem neurotypical, at least to me anyway - likely a helpful trait in the genre. It seems as though a common idea of the times that seems to be reflected in a lot of their writing, is an overdiagnosis of schizophrenia, and how it was generally used as a blanket term for anyone that just didnt think right.
I see loads of people holding pens weird ways I dont think it is a sign of autism.