Julian Jaynes coined a useful term in 1976 which I wish had gained currency before Jerry Fodor came out with The Modularity of Mind in 1983, because I think it captures all the useful aspects of the notion of “mental modules” without any of the misleading connotations. He defines it briefly in a footnote from The Origins of Consciousness(p. 31):
“Aptic structures are the neurological basis of aptitudes that are composed of an innate evolved aptic paradigm plus the results of experience in development. The term . . . is meant to replace such problematic words as instincts. They are organizations of the brain, always partially inate, that make the organism apt to behave in a certain way under certain conditions.”
“Aptic” is a particularly, well, apt term because its layers of meaning all fit quite well with what we’re expressing: it can mean both “prone/inclined” and also “appropriate”, the latter meaning deriving from the Latin aptus (“fitted/suited”). Aptus is the past participle of apere, meaning “to affix, fasten, attach” (etc.), which is itself derived from the Greek haptein, meaning “to fasten, to hold, to touch”. When this is prefixed with syn- (“together with”), we get synaptien, whence the word “synapse” for a biological process that functionally joins two neurons together. It’s also the same linguistic branch from which we get the Latin adaptere(“to fit/adjust”) and thence “adapt” and its derivatives, which is also fitting (heh) since these things are adaptations to the organism’s environment.