New research found lesbian and bisexual students face more discipline compared to their straight counterparts.

Ross Mittleman at Princeton University studied 5,000 students in 20 states over a 20 year period, according to PinkNews. He found that lesbians were 95 percent more likely to be punished than their straight peers and that only 38 percent of discipline risk was tied to behavior for those students.

“Part of it has to do with cultural conceptions of what it means to be a good woman or a good girl,” Danni Askini, the executive director of the Seattle civil rights organization Gender Justice League, said to the Union Bulletin.

According to the UB, the last study of LGBT student experiences was over 20 years ago. That makes the paper the one of the first to break down the issue after the legalization of same-sex marriage.

“In a context where seven states still have laws prohibiting any discussion of LGBTQ issues in schools, it’s been hard for researchers to collect measures of sexual orientation and gender identity from students as part of large-scale, education research programs,” Mittleman said to Princeton’s media relations department.