A literate reader knows the object-language's alphabet, grammar, and a sufficient set of vocabulary; a culturally literate person knows a given culture's signs and symbols, including its language, particular dialectic, stories,[1] entertainment, idioms, idiosyncrasies, and so on.
Enculturation seems to occur naturally, being intertwined with education, play, family relationships, friendships, etc.
One could become literate for an oral culture (with no written language or recorded media) only by extended conversation.
[3] This statement, especially the latter half, might be opaque to a reader from outside the United Kingdom, who does not know that "omnibus" is a less common British word for "bus" and "Hanwell" was the name of a (now defunct) insane asylum.
For example, social mobility increases when one is able to comfortably participate in conversation with gatekeepers like employers and teachers.