I’ll be the first to admit: for a long time, even after I’d begun my linguistics training, I didn’t really understand what sociolinguistics was. I had the idea that it mainly had to do with discourse analysis, which is certainly a fascinating area of study, but I wasn’t sure it was enough to serve as the basis for a major discipline of linguistics. Fortunately, I’ve learned a great deal about sociolinguistics since that time.
Sociolinguistics is the sub-field of linguistics that studies language in its social context and derives explanatory principles from it. By knowing about the language, we can learn something about a social reality and vice versa.
Now, at first glance this may seem so intuitive that it’s odd someone would to the trouble of stating it directly. As social beings, we know that the behaviour of people around us is informed by their identities and affiliations. At the extreme of things it can be things like having a cultural rule that literally forbids speaking to your mother-in-law, or requires replacing the letters “ck” with “cc” in all written communication. But there are more subtle rules in place as well, rules which are just as categorical and predictable and important. And if you don’t look at what’s happening with the social situation surrounding those linguistic rules, you’re going to miss out on a lot.
Case in point: Occasionally you’ll here phonologists talk about sound changes being in free variation, or rules that are randomly applied. BUT if you look at the social facts of the community, you’ll often find that there is no randomness at all. Instead, there are underlying social factors that control which option a person makes as they’re speaking. For example, if you were looking at whether people in Montreal were making r-sounds with the front or back of the tongue and you just sampled a bunch of them you might find that some people made it one way most of the time and others made it the other way most of the time. Which is interesting, sure, but doesn’t have a lot of explanatory power.
However, if you also looked at the social factors associated with it, and the characteristics of the individuals who used each r-sound, you might notice something interesting, as Clermont and Cedergren did (see the illustration). They found that younger speakers preferred the back-of-the-mouth r-sound, while older people tended to use the tip of the tongue instead. And that has a lot more explanatory power. Now we can start asking questions to get at the forces underlying that pattern: Is this the way the younger people have always talked, i.e. some sort of established youthful style, or is there a language change going on and they newer form is going to slowly take over? What causes younger speakers to use the the form they do? Is there also an effect of gender, or who you hang out with?
makingnoiseandhearingthings.com 
Reblogged this on Epenthesis and commented:
A good article on how linguistics has to do with everyday life.