Bullying is unwanted aggressive behavior by another person or group of people. In bullying, there is always an actual or perceived power imbalance, and the aggression is repeated multiple times or is highly likely to be repeated. Bullying also includes cyberbullying, a type of aggression that is carried out through electronic means, such as through the Internet, e-mail, or mobile devices. People of all ages can be bullied, and bullying may take place at home, school, or work. Because of cyberbullying, bullying can occur almost anywhere at any time.

About Bullying

Bullying is when a person or a group shows unwanted aggression toward another person.1 To be considered bullying, the behavior in question must be aggressive.2 The behavior must also involve an imbalance of power (e.g., physical strength, popularity, access to embarrassing details about a person) and be repetitive, meaning that it happens more than once or is highly likely to be repeated.2

Bullying can be2:

  • Physical: punching, beating, kicking, or pushing; stealing, hiding, or damaging another person's belongings; forcing someone to do things against his or her will
  • Verbal: teasing, calling names, or insulting another person; threatening another person with physical harm; spreading rumors or untrue statements about another person
  • Relational: refusing to talk to someone or making them feel left out; encouraging other individuals to bully someone

Bullying also includes cyberbullying and workplace bullying.

  • Cyberbullying has increased with the increased use of the social media sites, the Internet, e-mail, and mobile devices.3 Unlike more traditional bullying, cyberbullying can be more anonymous and can occur nearly constantly.3 A person can be cyberbullied day or night, such as when they are checking their e mail, using Facebook or another social network site, or even when they are using a mobile phone.3
  • Workplace bullying refers to adult behavior that is repeatedly aggressive and involves the use of power over another person at the workplace.4 Certain laws apply to adults in the workplace to help prevent such violence. Read more from CDC about occupational violence and laws to prevent it.


  1. Centers for Disease Control and Prevention. (2014). Featured topic: bullying research. Retrieved on January 28, 2014, from http://www.cdc.gov/violenceprevention/youthviolence/bullyingresearch/
  2. U.S. Department of Health and Human Services. (.). What is bullying? Bullying definition. Retrieved on August 7, 2012, from http://www.stopbullying.gov/what-is-bullying/
  3. Eunice Kennedy Shriver National Institute of Child Health and Human Development. (2010). Taking a stand against bullying. Retrieved on August 7, 2012, from http://www.nichd.nih.gov/news/resources/spotlight/092110-taking-stand-against-bullying
  4. U.S. Department of Health and Human Services. (n.d.). Workplace bullying. Retrieved on August 7, 2012, from http://www.stopbullying.gov/what-is-bullying/related-topics/index.html#workplace

Who is affected and how many are at risk for bullying?

People of all ages can be bullied. Bullying may take place at home, school, or work.

  • A 2013 survey from the National Center for Education Statistics found that bullying continues to affect many school-aged children1: Slightly more than 1 out of 5 students in middle and high school experienced “traditional” bullying at school during the 2012–2013 school year. Six percent of students ages 12 to 18 reported that they had been pushed, shoved, tripped, or spit on during the school year. Of these students, 22% reported being injured in the event.
  • The 2013 survey found that, during the same school year, 7% of students reported being cyberbullied.3
  • Data from the 2015 Youth Risk Behavior Surveillance System from the Centers for Disease Control and Prevention indicate that about 20% of U.S. students in grades 9 through 12 experienced bullying on school property within the last year.2


  1. National Center for Education Statistics. (2016). Indicators of school crime and safety: 2015. Retrieved September 1, 2016, from https://nces.ed.gov/pubs2016/2016079.pdf (PDF 2.8 MB)
  2. Centers for Disease Control and Prevention. (2016). Youth risk behavior surveillance system. Morbidity and Mortality Weekly Report, 65, 6. Retrieved June 17, 2016, from http://www.cdc.gov/healthyyouth/data/yrbs/pdf/2015/ss6506_updated.pdf (PDF 2.91 MB)
  3. National Center for Education Statistics. (2015). Indicators of School Crime and Safety: 2014. Retrieved June 17, 2016, from https://nces.ed.gov/pubs2015/2015072.pdf (PDF 4.14 MB)

What are common signs of being bullied?

Signs of bullying include1,2,3:

  • Depression, loneliness, or anxiety
  • Low self-esteem
  • Headaches, stomachaches, tiredness, or poor eating habits
  • Missing school, disliking school, or having poorer school performance than previously
  • Self-destructive behaviors, such as running away from home or inflicting harm on oneself
  • Thinking about suicide or attempting to commit suicide
  • Unexplained injuries
  • Lost or destroyed clothing, books, electronics, or jewelry
  • Difficulty sleeping or frequent nightmares
  • Sudden loss of friends or avoidance of social situations


  1. Eunice Kennedy Shriver National Institute of Child Health and Human Development. (2010). Taking a stand against bullying. Retrieved June 17, 2016, from http://www.nichd.nih.gov/news/resources/spotlight/092110-taking-stand-against-bullying
  2. U.S. Department of Health and Human Services. (n.d.). Who is at risk? Warning signs. Retrieved June 17, 2016, from http://www.stopbullying.gov/at-risk/warning-signs/index.html
  3. American Academy of Pediatrics. (2012). Health issues: School avoidance. Retrieved June 17, 2016, from http://www.healthychildren.org/English/health-issues/conditions/emotional-problems/Pages/School-Avoidance.aspx External Web Site Policy

How does bullying affect health and well-being?

Bullying can affect physical and emotional health, both in the short term and later in life. It can lead to physical injury, social problems, emotional problems, and even death.1 Those who are bullied are at increased risk for mental health problems, headaches, and problems adjusting to school.2 Bullying also can cause long-term damage to self-esteem.3

Children and adolescents who are bullies are at increased risk for substance use, academic problems, and violence to others later in life.2

Those who are both bullies and victims of bullying suffer the most serious effects of bullying and are at greater risk for mental and behavioral problems than those who are only bullied or who are only bullies.2

NICHD research studies show that anyone involved with bullying—those who bully others, those who are bullied, and those who bully and are bullied—are at increased risk for depression.4

NICHD-funded research studies also found that unlike traditional forms of bullying, youth who are bullied electronically—such as by computer or cell phone—are at higher risk for depression than the youth who bully them.5 Even more surprising, the same studies found that cyber victims were at higher risk for depression than were cyberbullies or bully-victims (i.e., those who both bully others and are bullied themselves), which was not found in any other form of bullying. Read more about these findings in the NICHD news release: Depression High Among Youth Victims of School Cyberbullying, NIH Researchers Report.


  1. Centers for Disease Control and Prevention. (2015). Fact sheet: Understanding bullying. Retrieved June 17, 2016, from https://www.cdc.gov/violenceprevention/pdf/bullying-factsheet508.pdf (PDF - 356 KB).
  2. Smokowski, P. R., & Kopasz, K. H. (2005). Bullying in school: An overview of types, effects, family characteristics, and intervention strategies. Children and Schools, 27, 101–109.
  3. Reece, T. (2008). Bullies beat down self esteem. Retrieved June 17, 2016, from http://www.healthychildren.org/English/safety-prevention/at-play/Pages/Bullies-Beat-Down-Self-Esteem.asp External Web Site Policy
  4. Eunice Kennedy Shriver National Institute of Child Health and Human Development. (2010). Taking a stand against bullying. Retrieved June 17, 2016, from http://www.nichd.nih.gov/news/resources/spotlight/092110-taking-stand-against-bullying
  5. Eunice Kennedy Shriver National Institute of Child Health and Human Development. (2012). Focus on children's mental health research at the NICHD. Retrieved June 17, 2016, from http://www.nichd.nih.gov/news/resources/spotlight/060112-childrens-mental-health

What are risk factors for being bullied?

Those who are at risk of being bullied may have one or more risk factors1,2,3:

  • Are seen as different from their peers (e.g., overweight, underweight, wear their hair differently, wear different clothing or wear glasses, or come from a different race/ethnicity)
  • Are seen as weak or not able to defend themselves
  • Are depressed, anxious, or have low self-esteem
  • Have few friends or are less popular
  • Do not socialize well with others
  • Suffer from an intellectual or developmental disability


  1. U.S. Department of Health and Human Services. (n.d.). Who is at risk? Risk factors. Retrieved June 17, 2016, from http://www.stopbullying.gov/at-risk/factors/index.html
  2. U.S. Department of Health and Human Services. (n.d.). Who is at risk? Considerations for specific groups. Retrieved June 17, 2016, from http://www.stopbullying.gov/at-risk/groups/index.html
  3. American Academy of Pediatrics. (2006). Teasing and bullying of obese and overweight children: How parents can help. Retrieved June 17, 2016, from http://www.healthychildren.org/English/health-issues/conditions/obesity/Pages/Teasing-and-Bullying.aspx External Web Site Policy

What can be done to help someone who is being bullied?

To help someone who is being bullied, support the person and address the bullying behavior. Other ways to help—including what to do if a person is in immediate danger—are listed below.

Support a child who is being bullied:1

  • You can listen to the child and let him or her know you are available to talk or even help. A child who is being bullied may struggle talking about it. Consider letting the child know there are other people who can talk with him or her about bullying. In addition, you might consider referring the child to a school counselor, psychologist, or other mental health specialist.
  • Give the child advice about what he or she can do. You might want to include role-playing and acting out a bullying incident as you guide the child so that the child knows what to do in a real situation.
  • Follow up with the child to show that you are committed to helping put a stop to the bullying.

Address the bullying behavior:1

  • Make sure a child whom you suspect or know is bullying knows what the problem behavior is and why it is not acceptable.
  • Show kids that bullying is taken seriously. If you know someone is being a bully to someone else, tell the bully that bullying will not be tolerated. It is important, however, to demonstrate good behavior when speaking with a bully so that you serve as a role model of good interpersonal behavior.

The "Bullying: Be More Than a Bystander" resource, which includes a presentation and facilitator's guide, seeks to educate people about taking action against bullying. It suggests you can help someone who is being bullied in the following ways:2

  • Be a friend to the person who is being bullied, so they do not feel alone.
  • Tell a trusted adult if you see someone being bullied.
  • Help the person get away from the bullying without putting yourself at risk.
  • Don't enable bullying by providing an audience.
  • Set a good example by not bullying.

If you feel that you have taken all possible steps to prevent bullying and nothing has worked, or someone is in immediate danger, there are other ways for you to help.3

The problem What you can do
A crime has occurred or someone is at immediate risk of harm. Call 911.
Someone is feeling hopeless, helpless, or thinking of suicide. Contact the National Suicide Prevention Lifeline online or at 1-800-273-TALK (8255). This toll-free call goes to the nearest crisis center in a national network. These centers provide crisis counseling and mental health referrals.
Someone is acting differently, such as sad or anxious, having trouble completing tasks, or not taking care of themselves.

Find a local counselor or other mental health services.

A child is being bullied in school. Contact the:
  • Teacher
  • School counselor
  • School coach
  • School principal
  • School superintendent
  • Board of Education
Child is being bullied after school on the playground or in the neighborhood
  • Neighborhood watch
  • Playground security
  • Team coach
  • Local precinct/community police
The child's school is not addressing the bullying Contact the:
  • School superintendent
  • Local Board of Education
  • State Department of Education

Table modified from http://www.stopbullying.gov/get-help-now/index.html3


  1. U.S. Department of Health and Human Services. (n.d.). Respond to bullying: Support the kids involved (Support kids who are bullied). Retrieved June 17, 2016, from http://www.stopbullying.gov/respond/support-kids-involved/index.html#support
  2. NICHD. (2015). Bullying: be more than a bystander (presentation). Washington, DC: U.S. Government Printing Office.
  3. U.S. Department of Health and Human Services. (n.d.). Get help now. Retrieved June 17, 2016, from http://www.stopbullying.gov/get-help-now/index.html

NICHD Bullying Research Goals

NICHD aims to understand the short- and long-term health effects of bullying, how the patterns of bullying have changed over time, and other information. NICHD’s research on bullying includes traditional bullying behavior (physical, verbal, and relational) as well as electronic aggression (“cyberbullying”).

Some of NICHD’s projects related to bullying include but are not limited to:

  • Examining the co-occurrence of different types of bullying, including physical, verbal, social exclusion, spreading rumors, and cyberbullying, as well as their physical and psychological effects
  • Determining the health and behavioral consequences of bullying, as well as the outcomes to those being bullied
  • Identifying characteristics and other factors that increase a child’s risk for being bullied
  • Determining the prevalence of bullying and being bullied among children from different countries and comparing rates across countries
  • Identifying changes in bullying patterns and frequency over time and how these differ between and among different countries

Bullying Research Activities and Advances

NICHD supports and conducts a range of research on bullying. In addition to its own research, the Institute collaborates with other NIH Institutes and organizations to further our understanding of bullying.

The following is only a summary of some of the Institute's efforts related to bullying.

Child Development & Behavior Branch (CDDB) research supports a number of projects related to bullying through its Social and Emotional Development/Child and Family Processes Program. Some of these include:

  • Identifying Positive Aspects of Youth Internet Use: The Next Step in Prevention (Michele Ybarra, Internet Solutions for Kids, Inc.)
  • Social Aggression: Growth and Outcomes (Marion Underwood, University of Texas at Dallas)
  • Bullying Prevention Intervention for Adolescent Primary Care Patients (Megan Ranney, Rhode Island Hospital)
  • Reducing Problem Behaviors Through PYD: An RCT of Restorative School Practices (Joie Danielle Acosta, RAND Corporation)
  • Development of the CABS: Child-Adolescent Bullying Screen (Judith Vessey, Boston College)

The CDBB is soliciting Small Business Innovation Research (SBIR) grants to develop and test games that address bullying and cyberbullying, such as games that raise awareness about bullying or help those being bullied cope.

Division of Intramural Population Health Research (DIPHR) research on bullying is aimed at understanding the prevalence and patterns in bullying and how they change over time. Some of the DIPHR projects related to bullying include:

  • Examining cross-national health trends in children, including the prevalence of bullying
  • Identifying bullying and victimization factors in school-aged children
  • Characterizing the link between cyberbullying and depression in both bullies and those who are victimized by bullies

Other NICHD-supported studies include:

  • Co-occurrence of victimization for several subtypes of bullying, including physical, verbal, social exclusion, rumor spreading, and cyberbullying
  • Predictors of being bullied, such as weight status and race/ethnicity
  • Likelihood of substance use among adolescents who have been bullied

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