In Orality and Literacy, Walter Ong suggests that what Jaynes attributes to the bicameral mind might be explainable by pre-literacy. He points out that Jaynes places the time for the breakdown of bicamerality around the time that the phonetic alphabet was developed, and that many of the characteristics that Jaynes attributes to bicamerality, e.g.:

lack of introspectivity, of analytical prowess, of concern with the will as such, of a sense of difference between past and future

are characteristics of oral cultures, including contemporary oral cultures.