When it comes to psychoepistemology, the development of individuality is probably the issue that fascinates me the most. Specifically, how it seems to be a relatively new development, and how many people can, and do, function without it.
"Western philosophy" is a very broad term, which includes all sorts of ideas, from the rationalist idealism of the Scholastics to the empiric materialism of the Positivists. All those different schools of thought, however, have one thing in common: they assume the psychoepistemology of an individual that perceives itself as an entity.
This is not to say that Western philosophy isn't collectivistic - it often is. However, even the staunchest of collectivists still has to frame his arguments in terms of an individualized mind. From Marx to Hume, every western author who argues against individuality, must do so by claiming that it is an illusion - that, although we clearly perceive it, it is somehow not so. Although that might seem intuitive to those of us who have a properly individualized psyche, this isn't the way many people think.
Whether you're talking about North American tribes like the Comanche or the Cherokee; South American tribes like the Tupi or the Ianomami; extremely collectivistic Asian nations like China and Japan; or more primitive African tribes like the Saan or the Masai - individuality is not part of the equation at all. Their epistemologies are not phrased in terms of an individual perceiving entities, but in terms of a loosely integrated being, who can "be possessed" by a number of different personalities, thinking and acting according to the situation he is in.
To better understand the difference, think of the mind of a child who hasn't yet adopted the primacy of existence, and still thinks in magical terms. When that child "plays cowboy", it doesn't merely "interpret" a role for fun, while being aware that it is not true - it truly perceives itself as a cowboy for a period of time, and believes it so intensely that if an adult acted that way, we'd call him delusional. That is exactly the psychoepistemology of primitive cultures - an animistic indigenous man, for example, "becomes" a bear when he's hunting, and later "becomes" a snake when he's hiding, only to then "become" a father when at home.
Although strange, the logic of this is quite straight forward. If one hasn't fully adopted the primacy of existence as a psychological principle, it is impossible to differentiate between "that entity", qua objective existent, and "that entity and all my thoughts and feelings associated with it", as that requires a previous differentiation between existence and consciousness. Without that differentiation, one cannot perceive oneself as an objective existent, with a specific identity, able to perceive other existents and think as an integrated being; but only as a vessel for "a specific character in a specific situation", able to perceive certain courses of action, and think in the context of a specific sub-personality.
I believe that, with all their many flaws, this was the fundamental discovery of Freud and the other psychoanalysts: the integration of one's personality isn't automatic, but a complex, active process.