Jarrod Reed, 14, said he had friends who were racist towards Maori and thought it was because of how they were raised.
Roos van Gorp, 14, said she was often expected to live up to the Dutch stereotype of being a hard worker.
This follows a University of Auckland study published in the New Zealand Journal of Psychology about racism and discrimination involving 695 Year 9 students.
Russell Gordon, principal of Mount Maunganui College, said young children who grew up with labels were scarred for life.
"It's self fulfilling and something we need to rid from society. If you have low expectations of yourself or if others have low expectations of you, you tend to meet those expectations every time. Something I believe is very important is if you aim for the moon, if you miss at least you hit the stars."
Otumoetai College principal Dave Randell said young people often picked up racial stereotypes from their elders and schools aimed to break that.
"At my son's school, he was the only white face in his rugby team. He wasn't even aware of that until it was pointed out, I think as adults we're responsible for a lot of the stereotyping and make these kinds of comments.
"Generalising people affects the way people treat each other."
University of Auckland researcher Dr Melinda Webber said the paper looked at whether or not a student's ethnicity formed who they were, how they belonged and what they were trying to achieve at school.
The paper found race influenced their relationships, affected how teachers dealt with them, and influenced how hard they tried at school.
Dr Webber said all of the high achieving students she interviewed had a positive identification with their race.
"This is a really important lesson for parents, they need to give their children a strong sense of belonging to an ethnic group because it makes them strong in the face of racism.
"Kids also need to be aware of the racism in their group. If they aren't armed with that knowledge, when it happens to them they freak out and start wondering if it is true."
Race Relations Commissioner Dame Susan Devoy said it was clear stereotyping of any sort could negatively affect a student's learning.
"This in turn affects how well a student does at school ... some young people are getting strong messages from the media and their own communities that they are 'dumb' or less likely to succeed.
"The Commission calls this "structural discrimination" and we, communities, government, schools, families, share a responsibility to address it or we will continue to see persistent inequalities in educational outcomes."
Tauranga counsellor Bergen Gell said to get out of these stereotypes, teachers, parents and authorities needed better support.
She said a lot of racism was also bullying and that needed to be addressed.
