The first step in knowing how to deal with girl-on-girl meanness is to understand where it comes from
Editor’s Note: This story was a part of the series You can do it, which ran in the Spring 2026 issue.
Photo Credit Depositphotos
Welcome to life as parent or guardian to a girl.
Unfortunately, this is not an unusual occurrence. The first step in knowing how to deal with girl-on-girl meanness is to understand where it comes from.
According to Tracy Vaillancourt of Counselling Psychology, Faculty of Education at the University of Ottawa and past-president of the International Society for Research on Aggression, meanness in girls is a taught behaviour.
Tracy Vaillancourt. Photo Courtesy Tracy Vaillancourt
“Mean girl behaviour is a combination of many things,” says Vaillancourt. “First of all, we teach little girls that nice girls don’t hit. But they’re often still competitive. So instead of physical aggression you end up with relational aggression. Boys are quite different. They get that message much later.”
Vaillancourt says that the subtle aggression or meanness amongst females is nothing new.
“This meanness, which is really a need to compete, has been going on for thousands of years amongst females,” says Vaillancourt. “It’s like a survival technique for you and your offspring.” In the past, much of the competitive meanness springs from a lack of economic security.
Mean girl behaviour is also learned. “Women and girls are very good at understanding emotional cues and the way that a mean message is delivered can be very subtle,” says Vaillancourt. “Even when that message is meant to cause harm or distress, plausible deniability is used as a shield.” She says excuses like “oh, you’re just too sensitive,” or “you took it the wrong way” are clever ways to gaslight someone.
Anatomy of a mean girl
There are particular personality traits that are associated with mean girls. Many so-called mean girls are hyper competitive, and they use meanness because it makes them feel powerful, says Vaillancourt, adding that unfortunately, many mean girls are also very popular, so they don’t get called out for their behaviour.
“More often than not, mean girls become mean women and that can have serious social implications in later life,” Vaillancourt says. She continues: if a person were to suspect their daughter of mean behaviour, they need to help them.
“You have to ask them and probe why they are feeling triggered to be mean,” she says. “They can practice this behaviour on their siblings. If one child is exerting power over another and getting away with it, they’ll keep doing it and use that behaviour on others.”
Vaillancourt advises parents to be direct and be able to say that this kind of behaviour is not appropriate.
“You have to say, ‘we don’t do this’ and mean it,” she says. “You can tell them that you understand their frustration, but that there are consequences for mean behaviour.”
Back up your child’s teachers
Vaillancourt says that educators are good at spotting mean girl behaviour and they have been trained to take it seriously.
“If you get a call from your daughter’s school about unacceptable mean behaviour, take your child’s teachers seriously,” says Vaillancourt. “Don’t be defensive. It might be an uncomfortable conversation, but teachers are there to help.”
Vaillancourt’s upcoming book, Mean, will be published in 2027 and will contain solutions and advice for parents.
She is also a member of PREVnet, a national not-for-profit organization dedicated to preventing youth interpersonal violence. The organization collaborates with communities, organizations, educators, researchers, and youth to create and share learning resources that address bullying and teen dating violence across Canada.
Deinera Exner-Cortens is the scientific co-director at PREVnet.
Deinera Exner-Cortens. Photo Courtesy Deinera Exner-Cortens
The organization was founded in 2002 and began with a focus on child and youth bullying.
“Mean girl behaviour is very much of form of bullying,” says Exner-Cortens. “Girls are particularly good at verbal meanness because of their advanced language skills; they fight with words.”
“Unfortunately, because it’s not physical and often less obvious, it gets a pass as being socially acceptable, but it still causes harm.” As Vaillancourt also points out, Exner-Cortens agrees that mean girls are often popular. “It’s the kind of behaviour that might work well in middle school or high school,” says Exner-Cortens, “but it’s not mentally healthy for anyone.”
PREVnet provides research-based information to parents and educators about bullying. Exner-Cortens says, “and we are very accessible for parents and children as well. For young people, we have advice on what to do if you are bullied. And for parents on what to do if it’s your child that is doing the bullying. It’s useful, direct information to help support healthy relationships.”
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Did you know?
PREVnet has over 130 researchers and represents 30 academic institutions across the country.
Useful websites
profiles.ucalgary.ca/deinera-exner-cortens
Signs your child is being bullied
- Afraid to go to school
- Unhappy and irritable
- Says they are feeling unwell
- Declining interest in activities
- Isolated from their peer group
- Injuries or bruising
For more information: prevnet.ca/bullying/signs-of-bullying/
What can parents do?
- Let your child know you want to hear about their experiences
- Encourage your child to be assertive and report bullying
- Create positive environments
- Promote healthy relationships in the family
For more information: prevnet.ca/bullying/facts-and-solutions/