Even in 2016 gay teachers and students are often too scared to come out, especially in conservative or religious schools.
The resulting statistics may explain why, with nearly half of all gay students suffering assault at school because of their sexuality, leading to higher rates of truancy, depression and self harm.
One teacher at Wellington's Newlands College is trying to combat those attitudes, and help students at his school who are grappling with their sexuality.
Jerome Cargill is gay. He doesn't advertise the fact, but the students know, having made a conscious decision eight years ago when he started teaching that he would not live a lie.
"What changed for me is learning what a difference it can make for students that are doing their own questioning," he told Seven Sharp.
There are seven teachers at the college who are gay, including deputy principal David Pegram.
"I've always thought of it as a position of strength and once you are out in a school you are in the commanding position rather than weak position and if you are not out at school and kids know you are automatically in a defensive, hiding, secretive, vulnerable position," he says.
Two years ago Mr Cargill and science teacher Kirsty Farrant announced they were forming a group to support queer and gender diverse people at the school.
They meet in secret once a week, and there are 15 members.
One student, Josh, says they group helps those who are wanting to tell their family.
Mr Cargill says it's upsetting that some schools aren't as progressive.
"Extremely hurtful to hear some principals say that they don't need to cater for gay students because they don't have any. That's just wrong. They just aren't providing environments where gay students are out."