WASHINGTON — Every Sunday afternoon, football fans will be ejected from stadiums nationwide for doing things we expect them to do: acting drunk, verbally harassing the other team and its fans, pouring beer over someone’s head and calling him a “self-righteous Belichickian.”

The National Football League released an official code of conduct for spectators last month. With it, the NFL seems to say, “Let’s keep this civilized, you animals.” Sip your beer, the NFL urges, but don’t guzzle it. Cheer for your team, but don’t curse. Instead of getting pulled into the rowdiness in a nearby row, send a text message to stadium security. They’ll swoop in and defuse the situation, and you can remain anonymous.

Civility, historically celebrated in lofty axioms by noble peoples, has evolved over the past decade into a full-on movement of the masses. It’s being trumpeted and incorporated by universities and private associations, by entire municipalities, by Internet users yearning for an online code of conduct and, yes, by a professional sports league that seems to exist solely to sell beer to adrenaline-pumped hotheads.

Tracts on manners have been written for hundreds of years. During his childhood schooling, George Washington, for example, transcribed the 16th-century “Rules of Civility & Decent Behavior in Company and Conversation,” which includes this quaint maxim:

Put not off your Cloths in the presence of Others, nor go out your Chamber half Drest.

Curiously, the NFL omitted that rule from its code.

The point is, we’re no longer focused on how to formally address royalty (protocol) or which fork to use first (etiquette). Now we’re simply lobbing official reminders at one another to keep things cool.

We’ve evolved into a highly technical, accomplished, more egalitarian society over several millennia, but we still need encouragement to be kind and decent and deferential.

Does that mean we are any less civil today than in the past?

It’s always risky to compare eras, cautions P.M. Forni, founder of the Civility Project at Johns Hopkins University and author of “The Civility Solution: What to Do When People Are Rude.”

In certain ways we are more civil. In other ways, especially when it comes to traditional forms of deference, we are losing ground.

“An example I use often is that of a pregnant woman on a bus,” Forni says. “Maybe there are fewer youngsters that give their seat on the bus to the pregnant woman today than there were generations ago. But when that woman steps into her workplace today, the number of men who consider her a professional and intellectual peer is higher than in my father’s generation.”

Alinda Lewris, the volunteer executive director for the International Association of Protocol Consultants, has interviewed chief executives of Fortune 500 companies to understand the impact of incivility in the workplace. Data from the past 10 years suggest that we think society is getting less civil, that workplace bullying is rising and that co-workers, for the first time, are the No. 1 cause of work-related stress.

“It’s not just in the workplace, but almost in every venue, be it at the movie house or on the road or in a hospital,” says Lewris.

Or in a football stadium.

But the NFL’s new code of conduct seems to have improved the spectating environment, at least anecdotally, says the league’s vice president of security, Milt Ahlerich.

Last week he was at FedEx Field, looking over the shoulder of the employee in charge of receiving text messages from irritated Redskins fans. Messages are passed to security workers, who then visit the offending seat, row or section to enforce the code. It’s citizen watching citizen for the good of civility. Ahlerich calls it “fan empowerment.”

What about the fine line between having a rowdy good time and offending other people?

“There’s not a scientific formula here, but generally we’d say that when you are repeatedly interfering with others fans’ experience, then you’re over the line,” he says. “Can you cheer loudly? Absolutely. Can you be enthusiastic and disappointed? You certainly can. Can you assault or harass someone who’s wearing another team’s jersey? No, you cannot.”

The tension in a football stadium makes it a ripe venue for rude behavior. Stress, in fact, is one of the four main causes of incivility, Forni has concluded. The others are time (hurried, disrespectful manners), self-interest (the preoccupied teenager not noticing the pregnant woman on the bus) and anonymity.

House Nancy Pelosi, D-Calif., at the liberal bloggers’ Netroots convention in July provided a keen example of how incivility benefits no one. The forum was addled by protesters bent on causing a ruckus, not contributing substantive objections to the debate, Netroots founder Gina Cooper says.

The same can be said for the heckling during Sen. John McCain’s acceptance speech at the Republican National Convention this month.

There’s a difference between calmly expressing frustration and disrupting an event.

Either way, Cooper expects online anonymity to erode as we live our lives more and more online. This may lead to more self-restraint.

Lewris envisions ever-increasing dialogues on civility. Forni would like to see civility become a concrete part of school. Regardless of these expectations, at least people are talking about it more today than in past generations. But are we really more likely to act civil if there are codes telling us to do so?

“It depends,” Forni says. Codes “can have a backlash effect. We don’t embrace codes very gleefully. What we do know is good manners and civility and politeness can be taught, especially to children, with very good effect. We know, for instance, that youngsters who have been trained in civility-based relational competence are less likely to become abusive and violent adults. ...

“Civility, politeness and good manners are not trivial, because they do the everyday busywork of goodness.”