Is it known why so many of the races of Tamriel display a sixual dualism? Since the et'Ada have no six, that is they cannot be male or female, and Mer and Men are descendants of the divine then why hasn't this trait been conserved? Rather than having races with male and female counterparts should there not be a single six - that could reproduce asixually perhaps? Even Argonians who are assumed to be created by the hist show this dualism. I understand it was probably just a gameplay choice initially but I'm not sure if this has actually been explored in the lore; the closest I have come to an explanation is in http://www.imperial-library.info/content/notes-racial-phylogeny-and-biology which describes the interfertility of the races and mentions "magickal experimentation," and "gradual changes from one generation to the next," which seems to suggest some form of Nirnian evolution. So I wonder, then, if the common races were originally monosix and then eventually split as a result of dawn-magick mutation.

http://www.imperial-library.info/content/skyrim-monomyth to the rescue!

"..These are spirits made from bits of the immortal polarity. The first of these was Akatosh the Time Dragon, whose formation made it easier for other spirits to structure themselves. Gods and demons form and reform and procreate.

Finally, the magical beings of Mythic Aurbis told the ultimate story -- that of their own death. For some this was an artistic transfiguration into the concrete, non-magical substance of the world. For others, this was a war in which all were slain, their bodies becoming the substance of the world. For yet others, this was a romantic marriage and parenthood, with the parent spirits naturally having to die and give way to the succeeding mortal races.."

"..But this was a trick. As Lorkhan knew, this world contained more limitations than not and was therefore hardly a thing of Anu at all. Mundus was the House of Sithis. As their aspects began to die off, many of the et'Ada vanished completely. Some escaped, like Magnus, and that is why there are no limitations to magic. Others, like Y'ffre, transformed themselves into the Ehlnofey, the Earthbones, so that the whole world might not die. Some had to marry and make children just to last. Each generation was weaker than the last, and soon there were Aldmer.."

six and death were invented as a means to keep on existing.

Just because women or females are ignored in the lore, does not mean they were not part of the lore. It just means the lore (or history) was written by a man. In fact, the word History gives the biggest clue as to why one gender gets mentioned more often or even exclusively when reading the old stories.

Sorry though the stuff on The Monomyth is interesting I wasn't actually referring to sixual intercourse I was referring to anatomical six, of being either male or female. Even though they had to have six and reproduce to continue existing they still did not have to polarise the races into male and female halves - and why they chose to polarise like this is what I'm wondering.

My point wasn't whether they're ignored in the lore, my point was why there is a sixual dualism. Why not just a hermaphroditic monosix? Why did the earthbones choose to manifest their mortal form as a duality of male and female?

To continue the overarching pattern of duality of the Aurbis perhaps. Anu - Padomay, two seperate and discreet entities on who's interplay the Aurbis is formed.

Male - female, two seperate and discreet entities who's interplay similarly creates something new.

Oh, yes. This is a good explanation actually and I'll probably use this as headcanon, thanks.