Upvote:5
There is also a simple geographic explanation to this issue. Mountains divide people, rivers bring them together. If you look at the most stable boundaries in the world, they are those that are along mountains.
The Caucasuses are, of course, highly mountainous. For protection, for food, and for simple energy conservation, once a culture is established on a mountain, it's hard to move it. And, as different groups establish themselves on different mountains, they tend to differentiate. Simple time encourages mistaken kingdoms to be small and varied - and the Caucasuses, like most mountainous areas (the himalaya, the Appalachian, The Alps) tend to encourage lots of small micro cultures.
Upvote:10
Here's my proposition, basically it's just a set of Caucasus characteristics making this region especially interesting. By which we mean: there're numerous languages, 3 distinct language families, characteristic just for this region.
My first point is, language diversity / fragmentation is normal for regions without a strong state / commerce / any unifying factor. The local societies tend to isolate from each other, hence many different languages emerge (and the isolation is stronger in mountainous realm of valleys, where travelling is simply hard).
Take pre-Columbian America for instance, aboriginal Australia, pre-Roman Italy, or to some extent - even modern European countries, in 18th century Spain, Aragonese, Leonese, Fala, Galician were spoken by significant population (not to mention Basque, Catalan, Valencian and Andalusian). What happened to Aragonese? Integration with Castille, and raise of national state has put this language in danger. What happened to old Italic languages? Rise of Roman state and culture swept them out.
On the other hand, what happened to all these extinct Celtic languages? They were swept by subsequent waves of German and Slavic migrations.
So the reasons for the Caucasus situation in contrast to that of Europe, in my opinion are: