My memory fades on how I ended up subscribing to https://medium.com, but there is often a post in their emailed Daily Digest that I find interesting.
Among the more recent medium.com posts was this one here, drawn from The Economist magazine, which featured the graphic below.
Whether Papua New Guinea should be counted as being part of Southeast Asia or not is a good question for another post, but even accepting that it isn’t part of the region still means that close to a third of the world’s language diversity is in Southeast Asia (and in just three Southeast Asian countries).
Why these three countries? I’m gong to hazard a guess, which is always dangerous as the readers of this blog tend to be awfully clever and kindly send me links to experts whose opinion is often greatly at odds to my own, but here goes.
I suggest, in a Southeast Asian context, there are two reasons.
The first is the island effect. Indonesia and the Philippines are great examples of that, and in combination present the greatest language diversity on the planet. Just like the evolutionary effect of geographic isolation in places like the Galapagos Islands and Australia, groups of people left isolated on islands tend to go their own way linguistically.*
The second is the effect of mountains and valleys, which have historically acted effectively as islands in precluding contact with neighbouring people and forming pockets of resistance to outsiders that I touched on from different perspectives here and here. The very mountainous Papua New Guinea is the supreme example of that, and I would argue that the hills and mountains of Thailand (and Pakistan) also contribute to their position on the list. Furthermore these hills and mountains act as a diversity multiplier to Indonesia’s near countless islands, propelling the country to its astonishing language diversity behind only India, a country some four times its population size.
What a diverse and wonderful geographic neighbourhood Southeast Asia is.
* In the other direction, people brought togther through gobalising tools such as the internet tend to lose their language diversity, which is why you are all reading this in English no matter what your native language.