The Massachusetts Bay Transportation Authority is the nation’s oldest subway system, with traditions so enduring that the memory of Boston commuters runneth not to the contrary.

Like campaigns urging passengers not to be such thoughtless jerks.

Last week the MBTA rolled out the latest such campaign – a “Courtesy Critters” advertising blitz starring animals in the role of etiquette instructors. The 2,400 posters going up on trains and buses feature pigs reminding riders not to “hog a seat,” horses telling them not to “cause a stampede,” and a trio of elephants imploring: “Don’t spray your germs.” Another shows a flock of parrots in a subway car. “Don’t squawk on the phone,” it admonishes T users. “We hate to clip your wings, but not everyone wants to hear your conversation.”

Sound familiar? It was only 15 months ago that the T launched a campaign to go after seat hogs, open-mouth sneezers, and cell-phone blabbers with mock headlines reporting instances of polite behavior as if they were big news. “Man Gives Up Seat for Pregnant Woman!” announced one. Marveled another: “Couple Takes Own Trash from Blue Line Train!”

A year before that, the MBTA had enlisted Boston Celtics star Paul “The Truth” Pierce to record announcements chiding passengers to show common courtesy. “When you see someone who is elderly, disabled, or pregnant, don’t just sit there – offer them your seat,” Pierce urged. “Courtesy counts, and that’s the truth!” Earlier still had been the attempt to encourage more thoughtful behavior by handing out Dunkin’ Donuts gift cards to passengers who gave up their seats to the elderly or performed other acts of kindness.

The bad manners of Boston commuters is an old story (the Boston Elevated Railway was distributing a pamphlet on courtesy back in 1912), so I’m probably not going out on a limb by predicting that the new campaign isn’t going to make much of a difference. But I have been wondering what Mr. Oka would make of it.

I met Mr. Oka, who is in his 80s and walks slowly with a cane, during a visit to Japan in January. He had arranged to show me some historical sites in Tokyo, and we used the city’s vast subway network to travel distances too far to cover on foot. Several times, as we boarded a crowded train, I pressed him to take one of the few available seats. Invariably he refused, insisting that I take the seat.

“You are a visitor and my guest,” he told me. “It wouldn’t be right for me to sit while you stand.”

“But, Oka-san, you are much older than I am and you have difficulty walking,” I remonstrated. (Indeed, before we met in person he had warned me by e-mail that he was elderly and infirm.) “It would be disrespectful for me to take a seat and leave you without one.”

I remonstrated in vain. I tried a religious argument, telling him that the Bible enjoins believers to “stand up in the presence of the aged and show respect for the elderly” as a sign of reverence for God. Mr. Oka, a nominal Buddhist, wasn’t persuaded. On one train we actually had this debate in front of a row of seats designated for senior citizens – there was even a little sign depicting someone with a cane. Still he wouldn’t sit, so strong was his notion of what proper manners required.

Of course not every strap-hanger in Tokyo takes politeness quite so far. But based on my observations, courtesy and consideration for others are ingrained there to a degree that Green Line regulars would find astonishing. In a 10-day span, I must have boarded a subway, bus, or commuter train at least 50 times. Cellphones were ubiquitous, yet I never heard a ringtone – and only once did I see someone violate the taboo against talking on a cell in a public vehicle. Nor did I see passengers sprawl across three seats or leave sandwich wrappers and coffee cups in their wake. And though the rush-hour crowds in some stations were enormous, they managed to avoid the wrestling matches caused when riders insist on shoving their way onto a train before departing passengers can get off.

MBTA officials regularly observe that courtesy can’t be compelled, only suggested. “It’s unfortunate,” Transit Police Superintendent Joseph O'Connor said last year, “but there is no mechanism to force people to have good manners.” Yet there is such a mechanism, one that operates with striking effectiveness in the world’s busiest subway system: strong social pressure. Japanese commuters* expect* each other to be polite, mindful, and quiet. As a result, Japanese commuters mostly are polite, mindful, and quiet.

Courtesy really is contagious, even without cutesy animal posters. Alas, discourtesy is too, even with them.

(Jeff Jacoby is a columnist for The Boston Globe).