When the unconscious rises into consciousness through the individual it also immediately becomes a part of the collective consciousness that the individual has had to negotiate as he or she becomes an adult member of society. The dreams and visions of the individual go into the rituals and myths of the society from the unconscious to consciousness. Any bias in masculine or feminine is, therefore, immediate upon the contents of the unconscious entering consciousness. There are even some languages (none that I can speak myself) that have all of their words cast into two types: masculine and feminine.
So this question of the differences in feminine and masculine individuation is probably inseparable from the culture into which the unconscious contents arise. A good story always puts on some of the clothes of the society in which it is told, how else to involve the listener? No matter how far from that society that story may journey, it roots itself in the societies' collective consciousness.
If there is a non-collective difference between the sexes I suspect it will have to be tied to genetic-biological differences that impact the brain and these may be far removed from the common stereotypes we might apply through our cultural expectations. One controversial finding in brain studies is that of the difference in the timing of the lateralization of cortical functions. Regions of the cortex take on specific processing functions though of a nature still being studied and explored and not understood in any complete way by current science. These functional regions can be found mirrored on either side of the cerebral cortex which is divided symmetrically into the well-known two hemispheres.
http://dreamchimney.com/slvs/hemispheres_hi_20060828015808.jpgFrom what I understand, these functional zones can start off existing in both hemispheres, but, in some cases, will evolve into existing in only one hemisphere. This lateralization then, ends up with the function being in one hemisphere and not the other. The controversial claim (controversial as it is not clearly reproducible in experiments or studies) is that in men, lateralization occurs more quickly than in women.
Now this isn't even a brain structural distinction, but more of a brain functional distinction. So really this begs the question as to whether this is genetic or environmental. But it may be a distinction that male vs female gets mapped to by the unconscious. If individuals along gender lines in a given culture tend to have personalities that somehow reflect a more strongly "lateralizing" psychology vs a less strongly "lateralizing" psychology (what ever the heck that means), then our psyches may use that to sex the various characters in our dreams including ourselves. I have had a couple of dreams where I was a woman in it so I have the sense that while sexuality is strongly determined it is not an absolute quality of the ego. I suspect that there is some very deep duality in psychic development that sex is a best match to as a metaphor for a less physical psychic quantity.
My current guess is that there is a connective-separative duality in the psyche such that female dream characters tend to align to groups (in my psyche and my culture) and male characters tend to go their own way.
One can also make the argument that traditioinally and going all the way back to primate social behaviors, that males have competed aggressively with other males while females have ordered cooperative social structures. Perhaps the simple fact of the female body as the relatively vulnerable house of developing child might tend to skew social roles especially in our primate ancestors. Modern society which abstracts many of the cultural roles and even the process of meeting one's biological, instinctual needs reduces this difference to an ever less relevant factor. But the mild residual difference may persist and, if nowhere else, still inform those mythic stories we get from the unconscious.
