N recessively heritable? Like blue eyes? Like there's a perception gene with an S allele and an N allele (which we'll designate "s"), and if you cross 2 Ss parents you have a 25% chance of having an ss and thus intuitive child? Are you saying this because 25% of the American population is supposedly N?
I do think that it's partly genetic, as in, we're born with some aspect of it, or born with some built-in probability (predisposition) of being one or the other. And maybe our environment tips the scale to some degree. However, I highly highly doubt that this observational theory will neatly show up in our genes the way eye color does. Don't forget that the letters aren't functions in themselves.
EDIT: Hey, doesn't Captain Chick study genetics? Where is she? We need an expert!
as you probably know, we dont always follow simple Mendelian inheritance. humans are not always that simple! There can be:
complimentary (aaBB or AAbb both get the same pheno because both effect a chain of events...its important because it allows two "affected parents" aaBB x AAbb to have kids that are totally normal AaBb)
co-dominance (both A and b are expressed so its not black and white dom or rec in pheno).
recessive or dom epistasis (say for instance for many years it goes on as M or m being expressed and works all fine and well...suddenly that gene is totally not expressed in favor of another because another gene that is normally HH ends up as hh (through rare Hh x Hh parents meeting eachother) and thus when hh its, turns off Mm in favor of another pheno.
Polygenic: examples of this are height, skin color etc... many genes all with their own deal of working--anything from mendelain all the way to recessive epistasis--what ever you can think of all affect what looks like ONE trait.
also there can be mutant alleles and even multiple wild types. example is that maybe on factor of thinking is not a dichotomy of A a, but actually A, a+, a^,a- ...yet follows mendellian inheritance.
also there can be things like variable expression and incomplete penetrance all which affect how much a particular gene is expressed even if its "supposed to be" expressed.
Its vary possible that its entirely genetic without making everyone into a predicitable archetype.