Lingua Fascia

I have a(nother) fun theory that I like, but have no idea of the veracity of.

It's a two-parter:

1. I think people have an intuitive sense of someone's accent, only by sight.

2. I think it's because accents change faces.

My basic premise is that different accents and languages activate different facial muscles - the hypertrophy of those muscles, and their tension on the underlying bone, create different facial features. For example, Americans accents tend to carry a lot of open-mouthed vowel sounds - leading to larger-set jaws and wider features.

I think most people would tend to agree with this, at least on a surface level - although it strays uncomfortably close to racial and cultural stereotyping. Equally, I think there are some good alternative explanations or counter arguments (if there is any effect like this). Where do we draw this stereotypical of an accented speaker from? Does the correlation run in reverse - face shapes facilitating face shapes and therefore sounds, forming an accent? I'm I literally just thinking of Americans?

Anyway, I just think it's an interesting idea - so if anyone happens to know of a set of identical twins, separated at birth across a linguistic divide - can you send me some pics?