I have been reading The Master and His Emmissary by Iain McGilchrist, which is about the 2 brain hemispheres and how they each contributed to civilization (the book focuses primarily on western civilization) and I have noted similarities between the left/right hemispheres and 5/abos.
McGilchrist describes how the right hemisphere has a holistic view: its own body, others and the world are connected. It sees the world as a whole while the left hemisphere gaze is focused, detached and analytical.
The left hemisphere sees itself separate from the rest of the world (even from its own body), is self referential and sees everything in abstract and utility terms.
Schizophrenia for example shows high left brain activity when right brain activity would be expected.
Damages to the right hemisphere lead to a sense of detachment and a difficulty in understanding context, while damages to the right hemisphere lead to (among other things) an inability to use tools properly.
This last point obviously reminded me of the abos and from that I noticed other parallels also between Five's "family" and left brain characteristics.
RH has a tendency to imitate while LH to copy, RH with its view of reality as whole is more religious while LH tends to solipsism. RH observes the environment as a big picture while LH sees it fragmented.
RH accepts and appreciates the world as mysterious and unknowable while LH can't stand not knowing and is frustrated by unsolvable mysteries.
Both in 5th Head and A Story I think there is a representative from the opposite hemisphere such as David (RH) and the marshmen (LH) which have a tendency to the opposite hemisphere of the main character (David is more humanist where 5 is more attracted to the hard sciences, hillmen accept God as unreachable while the Marshmen seek him in the stars).
This duality can be found in other works of course but I find it quite prominent in 5th head.
I wonder if Wolfe did some research on the subject or was very intuitive as, according to McGilchrist's research, in the 20th century there has been a culmination in the left brain predominance in civilization and Wolfe saw that we are losing a certain way of thinking in our culture and world view (I think this can be seen in Peace too).
I think there would be much to discuss about the subject but I'm not a native English speaker (nor articulate enough) to do it justice but I recommend McGilchrist's book to anyone who finds this interesting.
P.S. Amazing podcast! One of my favorites