Are consonants more stable than vowels?

Question

I was trying my hand at an exercise to distinguish the different Sámi dialects (the exercise was used in the 2020 version of the Dutch Linguistics Olympiad). It gives nine words in all nine dialects and the mapping of one of those lists to a geographical area, and asks to map the other dialects to the other areas.

It seemed to me that some consonantal changes could be distinguished relatively easily (e.g. nasal assimilation and different strategies to avoid the /bd/ cluster), whereas there seemed to be much more variation in vowels and I could not easily tell which variant would be more original.

As I primarily work with Semitic languages I'm very used to looking at consonants first. This made me wonder: is it universal that consonants are more stable than vowels, is it just a coincidence that this happens to be so in both these areas, or is it because I'm used to looking at consonants that I find these easier to work with in Sámi as well?

_{(Please, no spoilers about the specific Sámi dialects, as I still want to figure out the rest of the exercise.)}

Answer 1

There are some factors that make vowels more volatile than consonants in general

• Consonants have fixed points of articulation and modes of articulation while vowels live in a continuous space
• In most languages, consonants have a higher surprisal than vowels, i.e., they carry more information

So vowels can shift around more freely than consonants. But this is just a tendency, since we observe a lot of consonant shifts in historical linguistics and dialectology. They just tend to occur at a lower rate and thus being slower than vowel shifts.