I didn't mean to imply intermarriage between neandertal and cro-magnon..
What I meant was, neandertal, being isolationist and territorial, tended to be suspicious of even their own kind..
Intermarriage between neandertal tribes was therefore, fairly uncommon, possibly with the exception of females captured during clashes between tribes.
Their natural tendencies helped to cause their demise..
They stayed in their own territories and defended them from outsiders, even among their own species..
I expect the introduction of Cro-Mag made them even more insular..
Cro-Magnon, on the other hand, while they had their tribal clashes, also seemed to have found room for "nuetral ground", for gatherings, trade, etc.. ( and maybe a little wife-swapping, or other trading in females, be it on a simple barter basis, mutual interest like tribal alliances, or whatever.. )
The motivation for isolationism is obvious-- outsiders bring disease, try to enslave, etc (am I sounding like Willy Green yet?). So it does fill a crude need for survival. It takes a bit of sophistication to understand the value of adventure and meeting new people for its own sake--and balance that with the necessary safeguards. It really is possible to have borders and trade at the same time. In fact, history shows that the nation with the best trade ends up with the best borders..
BTW, Drum, it's a pleasure meeting you too.