COLUMN ONE : Violence Born of the Group : The beating of Rodney G. King follows patterns observed by researchers. Police, the military and other embattled entities are especially susceptible.

The sight of a handful of Los Angeles police officers beating an unarmed black man while nearly two dozen other uniformed officers stood by and failed to intervene may have shocked the public, but it comes as little surprise to experts in group behavior.

They say the beating of Rodney G. King is a case of “us versus them,” typifying the tendency of tightly knit groups to divide the world into opposing camps, to devalue and dehumanize outsiders and, under certain conditions, to commit terrible violence against them.

In embattled groups such as the police or military, these tendencies are especially common, some psychologists say. Shared danger breeds intense loyalty and group identity. Over time, common values and common prejudices take root. Individualism fades.

Researchers see other patterns in group violence and the behavior of bystanders:

* The larger the group of attackers and the fewer the victims, the more savage the attack. One psychologist who studied lynchings found that large mobs not only shot and hanged their victims but left them “lacerated, mutilated, burned and flayed.”

* The presence of multiple bystanders in an emergency appears to reduce the chance that any one of them will step in. The incident somehow seems less urgent, and individual responsibility less clear, than when just one person is looking on.

* A witness may be less likely to step in when the victim is black. Some psychologists have found that groups of white bystanders are slower to help blacks than whites, as though the desire to conform outweighs the urge to help.

Now, experts say, the shocking videotape of the March 3 incident in Lake View Terrace, made unnoticed by a civilian eyewitness and broadcast widely, offers society an important lesson in the evil that can emerge from the insidious comfort of groups.

“It’s very difficult for societies to look at their faults and failures,” said Ervin Staub, a social psychologist specializing in the roots of evil. “When there is something that makes it very difficult not to do it, that’s a very important occurrence.”

Four officers were indicted and pleaded not guilty to criminal charges of assault and use of excessive force in the King incident, which occurred after the 25-year-old Altadena man--on parole after a robbery conviction--was pulled over for speeding after a short chase.

But at least 27 uniformed officers from several agencies were present at various times during the beating--21 from the Los Angeles Police Department, four from the California Highway Patrol and two from the Los Angeles Unified School District.

The role of those bystanders, and their apparent failure to intervene, is being examined by the same Los Angeles County Grand Jury that indicted the four officers. The panel is to return today to consider evidence on what the 23 others did or did not do that night.

To Staub, a professor at the University of Massachusetts at Amherst, the beating raises two obvious questions: Why would police officers hit an unarmed man more than 50 times? And why would 23 other officers stand by and not intervene?

The answers, Staub suggests, may lie in the nature of certain groups, especially those that tend to shape their members’ sense of self--often groups formed to do a job that is unusually demanding and dangerous, like law enforcement.

“Partly because they are doing something that is extremely demanding, they develop a strong ‘us-them’ orientation,” Staub said. “ ‘We as a group are special, we represent what is right . . . and we are willing to do what is required to do the right thing.’ ”

Forming groups is natural, psychologists say, and a strong group identity can build morale. Similarly, dividing the world into us and them is common, perhaps stemming from an infant’s discovery of the difference between his caretakers and strangers.

But in some groups, members manipulate the sense of “us versus them” to bolster group spirit and divert attention from internal problems. A sense of identity forms from denigrating outsiders. Members especially devalue outsiders they view as hostile.

“Certain ‘others’ are defined even more as ‘them,’ ” said Staub. “For example, people with whom the police are especially in conflict--because (to the police) they represent a lot of criminals, perhaps, and because they have set themselves in conflict with the police, right or wrong.”

Under certain conditions, such attitudes can lead to violence, Staub contends.

Police officers risk their lives daily, but have little power or privilege. They are called names and sometimes abused--experiences that can lead to feelings of anger and powerlessness.

“One of the most basic ways to gain a feeling of power is to exercise power over another human being’s body,” said Staub. “That’s a very elemental kind of power.”

Staub is a Hungarian-born survivor of the Nazi Holocaust who attributes his survival to Raoul Wallenberg, the Swede who risked his life to save European Jews. He has done extensive research in altruism and published a book on the origins of genocide.

During the late 1960s, in a study of young children’s behavior in emergencies, Staub noticed that their willingness to help increased until about the second grade, then leveled off and dropped significantly by the time they reached sixth grade.

“It seems to us that what may be happening is that kids learn social rules about appropriate behavior,” Staub said. “And these rules inhibit them at a time when the circumstances really call for help.”

In the course of Staub’s study, he placed each child in a room with a task to complete. Suddenly, there would be a crash in an adjoining room and cries for help. The older children justified their inaction by saying they thought it would be wrong to leave their assigned task.

But when the researchers gave the children permission to go into the other room--to get more pencils, for example--they reacted differently. One child heard the crash, listened, waited, picked up each pencil and broke it, then ran into the adjoining room.

“It was a dramatic illustration of the way the social world would inhibit bystanders from responding,” Staub said.

The power of such social norms may be evident in the King beating, psychologists say. They cite extensive research suggesting that whatever the values of individual members, they will become more extreme in a group setting.

The most important principle is that people do what is “normative,” or standard, in their group, one psychology professor said, adding: “If there is any single guide to predicting people’s behavior, it’s what they’ve done before in that kind of setting.”

Researchers also cited certain long-observed principles of mob behavior--in particular, the emergence of a “collective mind” even in a heterogenous crowd, and a lack of judgment, reasoning or critical thought.

They said the anonymity conferred by a crowd makes it possible for participants to abandon the sense of responsibility that normally controls individual behavior. Instincts and impulses can take over, rapidly infecting the entire group.

“There’s a widely held view that groups can produce in some instances . . . a retreat from adult levels of thinking and experiencing to more primitive, infantile levels,” said Steven E. Salmony, a North Carolina psychologist who has studied the Ku Klux Klan.

“The basic idea is an old one, that people get lost in a crowd,” said Brian Mullen, an associate professor of psychology at Syracuse University. “But specifically what gets lost is . . . the self-regulation processes that guide and direct everyday, intentional behavior.”

Certain factors, including the wearing of uniforms, enhance that anonymity, says Mullen, who has studied accounts of lynchings over 150 years. Released from self-scrutiny, “people’s behavior can quickly gravitate to the lowest common denominator.”

According to Mullen, members of a group tend to focus on whatever is unusual or different, just as one’s eye is drawn to one part of a picture and the rest blurs. A group’s attention centers on the rare thing, the outsider.

“When a group of people are victimizing a lone victim, they are paying a great deal of attention to that lone victim,” said Mullen. “They might notice the sounds that he makes or the dirt and blood on his clothing.

“But they don’t recognize that I, John Smith, am a father and husband. I have a job where I am sworn to uphold these rules, and the behavior that I’m engaging in violates that person that I am.”

But as early as the next morning, Mullen said, they wake up and say, “How could I have done that?’ When they examine their behavior in retrospect, they’re now bringing this attentional focus to themselves. . . . It’s simply that they were not paying attention.”

Staub draws a slightly different picture of the evolution of group violence. He believes that group members move along a “continuum of destruction”--from prejudice and stereotyping to small acts of mistreatment to more violent acts.

People change because they justify their actions to themselves, he says. They persuade themselves that victims deserve to be harmed. They engage in “moral exclusion,” deciding certain people are “not really human and that moral rules do not apply.”

Bystanders move along that same continuum, Staub believes.

“If you stand by and observe somebody else harming another person, and you observe the person suffering and don’t do anything, that’s very painful,” he said. “So what bystanders who remain passive tend to do (is) find reasons why this is right.

“People change as a result of their own actions. People who engage in helping behavior frequently become more helpful. People who engage in aggression that is not checked by others frequently become more aggressive.”

For that reason, Staub and others believe that the evolution to group violence can be slowed or halted if bystanders and group members object. Otherwise, those involved will believe that their actions are acceptable.

Staub also stresses the importance of strong connections between groups such as the police and the communities they work in--for example, joint projects, such as neighborhood improvement, that could benefit both sides.

“It changes the people who are involved,” Staub said. “It may make the policemen more caring, more thoughtful about the welfare of the people outside.”