Accents tell us a lot about the intelligence of the group of people using them for e.g. The American accent is stupid, literally.
Any american word, to be spoken with an american accent (which is nasal, annoying and sounds low-class) needs to be broken down into 2 primary parts or more, the interesting thing is that Americans are unable to pronounce the first part unless it is simple, they make the first part simple and second part complicated and speak accordingly by breaking the word in such a way e.g. Aluminium (aluminum)
Contrast this with the British accent (Classy, Posh, Pleasant and using full vocal range) they break the words into 2 parts too if needed but they are unafraid to say the more complicated part first and leave the second part simple, as an effortless afterthought eg. Aluminium (Alum-inium)
The entire manner of bearing and speech of a Britisher is much more superior and language indicators such as this are just one of the indicators albeit a very common and powerful one.
This can be extrapolated to any language and its' accent-speakers IQ and general personality traits of that society.