Claims that modern society is somehow more vulgar or coarse than our whitewashed memory of yore strike a chord with the thumb-twiddling conservative lurking somewhere around our left ventricle. Notions of equity with respect to ethnicity, faith, gender, sexuality or disability join a growing herd of sacred cows whose names we dare not utter lest we attract the scorn of the high-collared progressive checking his e-mail in our right atrium. This combination of historical myopia and a propensity to meddle, cross, and censure make for easy tirades against the slack moral fiber of society, often culminating in the all-too-frequent Sticking of Noses into the Business of Other People.
Indeed, we have substantial industries and endeavors devoted to the marginal refinement of our frumpy Civilization. Apart from assigning frequencies to operators, no small portion of the job of the FCC is to monitor the content of public (ha!*) broadcasts. Corporations hire sensitivity consultants to tell low-level executives not to pinch secretaries' butts. Concerned Mothers band together to oppose pornography, junior high school kids band together to oppose swearing, nonsmokers (probably many of them ex-smokers, like me) band together to oppose tobacco in public; banding together to oppose peeves is as common as it is noisome. The preceding list, as I'm sure you well know, is far from comprehensive.
*I chortle because radios and televisions are hardly public goods
So we have at least two possibilities: either society really has taken a significant turn for the worse and it needs to be corrected, or meddling meddlers like to meddle. Since I was born into the sordid debauchery of the 1970s, I can’t really vouch for the accuracy of claims of heightened moral turpitude (of course, it could always be a level effect, and not a growth effect), but there’s no shortage of evidence that folks have been wailing about the corruption of virtue since antiquity. After all, what were Luther’s theses if not a condemnation of vice? What indeed was the point of the Ten Commandments if not an indictment of the behavior of the Israelites? So, perhaps society has become more vulgar, perhaps not. While I find myself inclined to believe the latter, the more interesting investigation is in finding what factors lead to either refinement or vulgarity.
I submit to you that civility is the astroglide of social intercourse. Being nice is uncomfortable, but it is a discomfort we gladly bear when we expect reciprocation. Sure, putting it on is kind of gross, but imagine how much more unpleasant things would be in its absence.
So, as with other things, we adopt civility so long as the marginal benefit of it exceeds the marginal cost. In the event that being rude becomes relatively less expensive, we will naturally be more inclined to consume more of it. Heck, if you like, you can think of partisan politics as an example of the relative price of civility. Anonymity reduces the cost of rudeness, as it becomes less likely to be on the receiving end of unlubricated social contact.
Of course, all of this is on the margins. Plenty of people will be unfailingly nice to strangers no matter the circumstances. I call those people bozos because what are they going to do about it? Offer me a cup of tea and a biscuit?