This is an interesting question that Jaynes preferred to avoid discussing in interviews because of it's potential for controversy.
According to Jaynes, consciousness is composed of at least six different features:
3. Analog "I"
4. Metaphor "me"
Clearly these features can vary in different cultures as well as in different individuals. Let's consider a few examples.
First, in narratization we see ourselves as part of a life story extending on an imaginary timeline into our past and our future. In my research as well as discussions with people, I think this feature varies widely among individuals. Some people seem to be much more "present-oriented" while others seem to think much more about past events and decisions and how those events and decisions have influenced their current situation. They also tend to contemplate a range of possible future outcomes based on the current options available to them. The development of this feature of consciousness can perhaps be seen in studies of children that measure willingness to delay immediate gratification in exchange for some greater future benefit. This could be also be studied by comparing interviews with a person that, for example, holds up a liquor store vs. a person that applies to graduate school, to better understand the underlying thought processes. Another example would be those who have an inclination to save money vs. those who don't. In my conversations with people, among non-savers/future planners I often hear comments to the effect of "we could all be dead tomorrow" or "I never think that far ahead." Perhaps they have not been trained to develop narratization by their parents to the degree that the "future planner" has. In an interview Jaynes argues for the importance of hands-on parenting (instead of day care) to "teach" children to be conscious (in the Jaynesian sense) when they are very young. I would agree with Jaynes that it is largely a learned process but I wonder to what degree there might be a genetic and/or neurological component (frontal lobe dysfunction is thought to be associated with violence and lack of impulse control).
A second example is our internal dialogue (analog 'I' narratizing in a mind-space). We might be inclined to assume that all people share this feature to largely the same degree. But the research of Professor Russell Hurlburt at the University of Nevada, Las Vegas suggests otherwise. For several decades, Hurlbert has engaged in experiments he calls "Descriptive Experience Sampling" where participants are given a beeper and instructed to stop whatever they are doing and write down their thoughts when their beeper goes off. These experiments have revealed a wide variety of inner experience, with some participants allegedly having very little internal dialogue at all. See for example: Hurlburt, R. T., & Schwitzgebel, E. (2007). Describing Inner Experience? Proponent Meets Skeptic
Cambridge, MA: MIT Press.
Possible variations in individual Jaynesian consciousness could possibly also be discovered by studying individuals raised in highly authoritarian Muslim cultures such as found in Pakistan or Iran, who are instructed to engage in a range of consciousness-inhibiting activities such as the memorization of the entire Koran, mandatory repetitive verse recitation five times per day (Salat), etc. One could argue these activities are a form of brainwashing that diminish independent conscious thought in favor of strict adherence to established moral codes (bicameral-like external authorities). See, for example: Memorizing the Way to Heaven, Verse by Verse
Another area that could yield a greater understanding of differences in consciousness in individuals is children raised in isolation/abusive situations (often referred to as "feral children"). These children often have severe deficits in language ability due to lack of socialization, education, and parenting in general. One of the most famous cases is that of Genie in the 1970s. Another is the case of Joseph, as detailed by Oliver Sacks in Seeing Voices
. A more recent horrific case was uncovered in Austria in April 2008, in which several children were kept locked in a basement by their father, Joseph Fritzl. It remains to be seen if child psychologists working with such children document (or are even aware of) factors related to the current question.
Finally, those who have studied pre-literate and pre-modern people have documented apparent differences in conscious thought, one example being widely different perceptions of time (see for example descriptions of the Thai Boat People). This coincides with Chester Starr's argument that the early Greeks did not have a modern conception of time and history until as late as 500 B.C. In The Awakening of the Greek Historical Spirit
"Particularly in archaic Greece, which looked at its world through the spectacles of epic and myth and was still organized in a very primitive social and religious structure, the emergence of a sense of historical time could only be gradual and incomplete" (p. 59).
"To follow, then, the slow awakening of a historically oriented consciousness of time we must go back before philosophy itself had developed, and investigate the evidence of archaic poetry and art, as well as of the Greek language itself. Although this material adequately shows the reluctance of early Hellas to yield a sense of timeless continuity, the Greeks had come by 500 B.C. to a view of time in human affairs which made history possible, even essential, as a mode by which society explained its present character through the action of time in the past" (p. 60).
The Mentality of Pre-Literate and Pre-Modern Peoples
in this forum.
Study: Poverty Dramatically Affects Children's Brains
"Research has shown that the neural systems of poor children develop differently from those of middle-class children, affecting language development and 'executive function,' or the ability to plan, remember details, and pay attention in school."