DR. WALLACE: I know that bullying can be defined as someone big picking on someone small. Is that all there is? When I was a young teen, my older brother would threaten to do harm (he never did) if I told my parents that he was drinking beer (I never did). Was he a bully? I don't think so.

Please enlighten me on what you consider to be bullying? — Mom, Lake Charles, La.

MOM: The following definition of bullying consists of my thoughts on this despicable behavior and information I have gleaned from many different sources:

Bullying involves a person or a group repeatedly trying to do harm to someone who is more vulnerable. Bullying can be physical or verbal. It can consist of direct attacks, such as hitting, threatening, maliciously teasing and taunting, name calling, making sexual remarks, and stealing or damaging belongings. Or, it can involve more subtle and indirect attacks, such as spreading rumors or encouraging others to exclude someone.

While teenage boys target both boys and girls, teenage girls most often bully only other girls and use more subtle forms of aggression than boys. Girls are more likely to spread gossip or to reject or exclude another girl.

Victims of bullying can feel tense, anxious and afraid. Their concentration in school can decline; some begin to avoid school. Bullying can affect children's self-esteem. Some victims become socially isolated, leading to depression, anxiety and insecurity.

In extreme cases, victims feel compelled to take drastic measures, such as carrying weapons for protection or seeking violent revenge. Others consider suicide.

Studies show that adults who were bullied as teens have higher levels of depression and poorer self-esteem than other adults.

Teens, particularly boys, who bully are more likely to engage in other antisocial or delinquent behavior, such as vandalism, shoplifting, truancy and drug use, even into adulthood.

Teenagers who bully are four times more likely than non-bullies to be convicted of crimes by age 24, with 60 percent of bullies having at least one criminal conviction.

When there is a school-wide commitment to end bullying, it can be reduced dramatically. One effective approach focuses on raising awareness about bullying, increasing teacher and parent involvement, forming clear rules and strong social norms against bullying, providing support and protection for all students, and firm discipline for those who enjoy harassing another human being.

As a former high school principal, I am well aware that bullying can seriously damage a student's educational and personal development. It must be stamped out effectively and permanently. More than 160,000 American students will skip school each day this school year for fear of being bullied.

This is a disgraceful statistic, and the bulk of the blame falls squarely on the shoulders of the district superintendents and the school administrators, and of course, the bully's parents.

Dr. Robert Wallace welcomes questions from readers. Although he is unable to reply to all of them individually, he will answer as many as possible in this column. E-mail him at [email protected]. To find out more about Dr. Robert Wallace and read features by other Creators Syndicate writers and cartoonists, visit the Creators Syndicate website at www.creators.com.