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Understanding Bullying

Bullying is a form of youth violence. Although definitions of bullying vary, most agree that bullying includes: Attack or intimidation with the intention to cause fear, distress, or harm that is either physical (hitting, punching), verbal (name calling, teasing), or psychological/relational (rumors, social exclusion).

There is normally a real or perceived imbalance of power between the bully and the victim and/or repeated attacks or intimidation between the same children over time.

Bullying can occur in person or through technology (electronic aggression, or cyberbullying). Electronic aggression is bullying that occurs through e-mail, a chat room, instant messaging, a website, text messaging, or videos or pictures posted on websites or sent through cell phones.

A young person can be a bully, a victim, or both (bully-victim).

Why is bullying a public health problem?

Bullying is widespread in the United States.

boy with his hands on his cheeks
  • In a 2009 nationwide survey, about 20% of high school students reported being bullied on school property in the 12 months preceding the survey.
  • During the 2007-2008 school year, 25% of public schools reported that bullying occurred among students on a daily or weekly basis. A higher percentage of middle schools reported daily or weekly occurrences of bullying compared to primary and high schools.
  • In 2007, about 4% of 12- to 18-year-old students reported having been cyberbullied during the school year.

How does bullying affect health?

Bullying can result in physical injury, social and emotional distress, and even death. Victimized youth are at increased risk for mental health problems such as depression and anxiety, psychosomatic complaints such as headaches, and poor school adjustment. Youth who bully others are at increased risk for substance use, academic problems, and violence later in adolescence and adulthood. Compared to youth who only bully, or who are only victims, bully-victims suffer the most serious consequences and are at greater risk for both mental health and behavior problems.

Who is at risk for bullying?

A number of factors can increase the risk of a youth engaging in or experiencing bullying. However, the presence of these factors does not always mean that a young person will become a bully or a victim.

Some of the factors associated with a higher likelihood of engaging in bullying behavior include:

  • Impulsivity (poor self-control)
  • Harsh parenting by caregivers
  • Attitudes accepting of violence

Some of the factors associated with a higher likelihood of victimization include:

  • Friendship difficulties
  • Poor self-esteem
  • Quiet, passive manner with lack of assertiveness

How can we prevent bullying?

boy staring with neutral expression

The ultimate goal is to stop bullying before it starts. Research on preventing and addressing bullying is still developing. School-based bullying prevention programs are widely implemented, but infrequently evaluated. Based on a review of the limited research on school based bullying prevention, the following program elements are promising:

  • Improving supervision of students
  • Using school rules and behavior management techniques in the classroom and throughout the school to detect and address bullying, providing consequences for bullying
  • Having a whole school anti-bullying policy, and enforcing that policy consistently
  • Promoting cooperation among different professionals and between school staff and parents

How does CDC approach bullying prevention?

CDC uses a 4-step approach to address public health problems like bullying.

Step 1: Define and monitor the problem

Before we can prevent bullying, we need to know how big the problem is, where it is, and whom it affects. CDC learns about a problem by gathering and studying data. These data are critical because they help decision makers send resources where they are needed most.

Step 2: Identify risk and protective factors

It is not enough to know that bullying is affecting a certain group of people in a certain area. We also need to know why. CDC conducts and supports research to answer this question. We can then develop programs to reduce or eliminate risk factors.

Step 3: Develop and test prevention strategies

Using information gathered in research, CDC develops and and tests strategies to prevent bullying.

Step 4: Assure widespread adoption

In this final step, CDC shares the best prevention strategies. CDC may also provide funding or technical help so communities can adopt these strategies.

Where can I learn more?


  • Farrington, D. P. & Ttofi, M. M. School-based programs to reduce bullying and victimization. Systematic review for The Campbell Collaboration Crime and Justice Group; 2010. Available from URL.
  • David-Ferdon, C., Hertz, M. F. Electronic media and youth violence: A CDC issue brief for researchers. Atlanta, GA: Centers for Disease Control and Prevention; 2009. Available from URL.
  • Eaton, D. K. et al. (2010). Youth risk behavior surveillance – United States 2009. Morbidity and Mortality Weekly Report, 59 (SS-5), 1-142. Available from URL.
  • Robers, S., Zhang, J., & Truman, J. Indicators of School Crime and Safety, 2010 (NCES 2011-002/NCJ 230812). National Center for Education Statistics, U.S. Department of Education, and Bureau of Justice Statistics, Office of Justice Programs, U.S. Department of Justice. Washington, DC; 2010. Available from URL.
  • Smokowski, P. R., & Kopasz, K. H. Bullying in school: An overview of types, effects, family characteristics, and intervention strategies. Children and Schools, 27, 101-109; 2005.