Thread:User talk:CodeCat/Thanks./reply

I don't think it's really a conscious choice. Linguists haven't been able to identify any reason for language change. They only know that it happens, but they accept that it happens naturally and without any reason.

Contact among speakers often tends to level out differences between them. That can lead to rapid changes, when dialects adapt to each other. At the same time though, once the different dialects have more or less homogenised, there is a stronger tendency for the language to stay the same. So the process of establishing a wider standard language can accelerate change, but once established and accepted, it resists change. You can think of it like the larger language area has more "momentum": any change that happens must spread through the whole area for it to take hold, which is harder to do if speakers are aware of the change and resist it.

On the other hand, if a language variety is more prestigious (which Danish certainly was in Norway) then speakers are less likely to resist it and more likely to adapt to it. This is a very strong cause of language change, which you see many times in history. A new kingdom or other centre of power is established, and soon its language starts to spread into the whole territority. A classic example of this is Low German. It once was a highly prestigious language and influenced many others in its sphere, such as the Scandinavian languages, which took many words from it. But after its influence dwindled, High German took over its role and now speakers have mostly adopted High German as their "example".