Christian Roma during the pilgrimage at Saintes-Maries-de-la-Mer in France in the 1980s. (Photo: Wikimedia Commons)

It's no secret that adolescents—and adults who have never emotionally matured beyond an adolescent stage—feel a strong need to conform. In most cases, this isn't particularly problematic. But what happens when one of their peers decides to act with pointless cruelty? Do others follow?

Disturbing new research from Eastern Europe suggest they often do—and this tendency is greatly amplified when the victim is a member of a maligned minority group.

"Our results suggest that fragile social norms can lead to a sudden change in individual behavior toward other ethnic groups—from good coexistence to aggression," said Jana Cahlikova of the Max Planck Institute in Munich. She is a co-author of the study, which was published in the Proceedings of the National Academy of Sciences.

The study, led by Michal Bauer, featured 327 students from 13 schools in Eastern Slovakia. The kids were 13 to 15 years old; all belonged to the majority Slavic ethnic group.

The youngsters were introduced to what the researchers called the "Joy of Destruction" game. Each was given two euros, and then told they could spend one-tenth of that amount to hurt another player. If they made that choice, the other player would lose a full euro, or half their earnings.

Remember, players had to give up some of their own money to do this, and they received no benefits beyond schadenfreude—the pleasure one takes in the misfortune of others.

Each was provided with the last name of the person who would be hurt. It clearly indicated whether that person was a member of their ethnic group, or of the widely distrusted Roma, or Gypsy, population.

The kids were placed in groups of three. The second and third person were aware of the decision of their peer(s) when they made their own choice.

The researchers report the adolescents' behavior was strongly influenced by that of their companions. When the first decided to spend money to hurt another, it was far more likely that the second would as well.

But the rate of this imitation varied according to the ethnic group of the victim. Specifically, 51 percent of kids followed suit if the victim was an ethnic Slav. If the victim was a Roma, that number rose dramatically to 77 percent.

"Similar patterns emerge for subjects who observed the choices of two peers," the researchers add. They note that this effect was not limited to youngsters from lower socioeconomic backgrounds.

These are disturbing findings, particularly at a time of growing racial resentment and shifting group norms in many nations—including the United States. They suggest strong enforcement of hate crimes should be a priority, so such behavior can be snuffed out before it starts impacting others.

Aggressive ethnic hostility is contagious, and it's vital that we quickly stop the spread.