NPA personality theory
[ Post a Response | NPA personality theory ]
Re: Genetic heterogeneity and epistasis
Just to make the point that the NPA model allows for genetic heterogeneity. Namely, that there may exist several genes for the A− trait, so that the A− trait in one family may not be the same as the A− trait in another family. So besides the postulated COMT gene there may be several other genes that inhibit trait A, given the complexity of the biochemistry of the adrenergic neurotransmitters.
It should be stressed that the A locus of the NPA model does not really code for trait A. Rather, a dominant allele at the locus turns off, or inhibits, expression of trait A, allowing the existence of N and NP types. The recessive allele at the locus "allows" expression of trait A, which itself could depend on several causative and modulating genes at different loci ("epistasis").