Is it possible to tell something about the state of America by observing the behavior of theater audiences in New York and Boston? It may be. Although metropolitan playgoers are perhaps somewhat special, a trifle more sophisticated than those who crowd the movie houses, they are, in their way, representative. And their way today is better than it was in the 1960s, and the 1970s, too.
Not so long ago, going to the theater to see a great play or a lesser one or a musical was a social event of some importance. People dressed up for it, took their children when the performances seemed to warrant it, and followed a certain code of manners, comparable to that which obtained in their own homes.
There was nothing rigid or formidable about this, except perhaps on certain formal first nights in Boston when the atmosphere might be excessively cool. Playgoers were generally cheerful and friendly, anticipating a happy and perhaps memorable time in the presence of other cheerful, friendly people who could be counted on to share the fun while observing the proprieties. All that changed in the '60s when ''Hair'' brought in its rowdy rock 'n' rollers, most of whom shared its characters' fondness for unkempt clothing, unwashed hair, and noisy, rude, tribal conduct.
Theatrically, ''Hair'' shook up the world of theater from Broadway to Boston to Los Angeles, and abroad. It was sensationally successful in London and Berlin. And in Moscow and Leningrad, where its production was not allowed, every showman pumped every American visitor for any scrap of information about what it was like.
Broadway's composers were shaken and frightened by the possibility that the theater would spawn nothing but new and more anarchic versions of this landmark entertainment. But ''Hair'' closed eventually, and there were no prosperous successors. The theater returned to more conventional forms.
In the playhouses, however, the effect of that one show and what it represented in the world beyond was felt for a long time.
In New York, Boston, London, and Berlin, ''Hair'' spilled over its stages to put its performers in the audiences, and encouraged showgoers to share in the din and sin. When ''Hair'' at last faded away, its followers remained behind in the theaters. Or, at any rate, some of them did, and along with them came other young men and women who had been influenced and conditioned not only by that one production but by the mores of the American scene in which it was engendered.
Informality in dress, manners, and conduct came into the playhouses with them. Although they didn't take off all their clothes, as some of the performers in ''Hair'' did at the end of Act 1, they shed what they could before or after entering the theater, piling up coats on whatever seat was handy, sitting sometimes - the men, that is - in T-shirts.
Their generation disliked chairs, which seemed to betoken the formality of their parents' homes. In school and college huddles they had learned to sit on the floor. In the theaters they couldn't do that, but they could and did sprawl.
Their elders had long since learned that most theater chairs are somewhat constricting, forcing a certain upright position which, after three or four acts (as in an O'Neill play) can be tiring. The young newcomers slid down in the chairs to get their feet under the seats in front or, more often, projected their knees (which always seemed bony!) into the backs of the playgoers immediately ahead. When they got ''end'' seats, they invariably thrust their legs, which seemed surprisingly long, out into the aisles, extending them just as far as they could possibly reach.
A Boston reviewer, attending the matinee of a Broadway play a few years ago, was astonished to discover that he alone of all those sitting ''on the end'' of the first nine rows was not projecting his legs away out into the aisles.
Some of this bad-mannered sprawling has been attributed not to the bad habits of the ''Hair'' generation but to an American custom of sprawling in front of the TV set. But there is, of course, a connection.
The good news today is that all this seems to be changing. While occasional young showgoers still seem to feel they must peel, removing coats and rolling up sleeves on taking their seats, the majority, young or old, no longer do. Formal dress is uncommon; first-nighters rarely go back to black ties and long gowns. But most are now dressing with some sense of what used to be called ''propriety, '' and many of the ladies - and there are still some ladies - are beginning to dress up.
More important, the general behavior of these audiences of the '80s has improved enormously. They sit and listen patiently, and for the most part quietly, and where their predecessors were generally downright rude they are by and large notably polite.
The heirs of ''Hair'' pushed their way to their seats like footballers. The new showgoers make an effort to stay off their neighbors' feet when entering a row of seats - an admittedly difficult thing to do - and, to the astonishment of those who have been going to the theater for a long time, are invariably apologetic for disturbing, or seeming to disturb, their neighbors.
They are, moreover, not only polite but also cheerful and almost invariably pleasant.
Is it too much to suggest that this change in the behavior of our theater audiences reflects a new attitude, a new social decency, on the part of the general public?
Reading some of the headlines, the temptation is to think of our world as a jungle. But we are not all savages. There are many decent, thoughtful people out there; people who respect one another's rights and do it cheerfully.
These theater audiences are a microcosm. They represent something that has changed for the better in our world during the last 20 years and that, in the long line of the centuries, is not an extraordinary period of time.