Raising teenage girls can be a tough job. Raising black teenage girls as white parents can be even tougher. Aaron and Colleen Cook knew that when they adopted their twin daughters, Mya and Deanna.

As spring came around this year, the girls, who just turned 16, told their parents they wanted to get braided hair extensions. Their parents happily obliged, wanting Mya and Deanna to feel closer to their black heritage.

But when the girls got to school, they were asked to step out of class. Both were given several infractions for violating the dress code. Mystic Valley Regional Charter School, north of Boston, bans hair extensions in its dress code, deeming them "distracting."

When administrators asked the girls to remove their braids, Mya and Deanna refused.

The next day, Colleen and Aaron Cook came to the school where, they say, they were told the girls' hair needed to be "fixed." The Cooks refused, telling administrators that there was nothing wrong with the hairstyle.

Mya and Deanna Cook, 16, with their parents, Aaron and Colleen Cook.

As punishment, the girls were removed from their extracurricular activities, barred from prom and threatened with suspension if they did not change their hair.

According to Colleen Cook, administrators at Mystic Valley have routinely reprimanded black students for dress code violations involving hair.

Other black girls have been pulled out of class, she says, lined up, asked if they had hair extensions and given detention if they did.

Colleen remembers when one student, who wore her hair in its natural texture, was taken out of class and told that she would need to relax, or chemically straighten, her hair before returning to school the next day.

In defense of their daughters, the Cooks brought in a yearbook to show school leaders the many white female students with hair extensions and dyed hair.

But, the Cooks say, the administration didn't see that those students were in violation of the dress code, stating those hair alterations weren't as obvious.

NPR reached out to Mystic Valley Regional for an interview several times without a response.

The Cooks contacted the NAACP, Anti-Defamation League and ACLU to file a complaint against the school, calling the dress code discriminatory to students of color, particularly black females.

After much pressure, the school suspended enforcement of the dress code until the end of the year.

Noticing a trend In recent years, black girls have been sent home for wearing dreads, head wraps and even wearing their hair naturally. In schools across the country, black student suspension rates are higher than their peers'. In charter schools, kindergarten through eighth grade, those rates are even higher.

In fact, Daniel J. Losen, director of the Center for Civil Rights Remedies, found that at the highest-suspending charter schools in the nation, the majority of students were black.

Though databases for infractions vary from state to state, in a recent analysis, half of suspensions in charter schools were for minor nonviolent offenses, including dress code violations. Specifically, Losen's research shows that in Massachusetts, the Cooks' home state, black students at charters lose 24 more days of instruction to suspension than do white students.

"Having a dress code is one thing, but denying an education for it defies logic," says Losen.

Zero tolerance leads to high suspension rates

Dorinda J. Carter Andrews, assistant dean of equity outreach initiatives at Michigan State University, says that black females are more likely to receive harsher discipline than their white and Latina counterparts.

Her research on zero tolerance policies and their outcomes shows that they enforce a marginalization of black girls in schools. Which can, in practice, criminalize their black identity.

"What does a headdress have to do with learning and success?" asks Carter Andrews.

She finds it strange that hair would even be part of a dress code. It's not a choice, but an aspect of one's body. Which raises a question: Is a zero tolerance policy for hair — where students can be suspended without warning — less about a dress code and more about a racial code?

In her research, Carter Andrews has found that this type of policing has a detrimental effect on black girls in schools and how their peers view them, further enforcing negative stereotypes.

Black girls are often seen as being loud or aggressive and are overly disciplined because of that stigma. Andrews finds that leads to low self-esteem and underperformance in school for these students.

Jamilia Blake, who looks at the "adultification" of black girls in schools, believes stereotypes of black adults are put on black children in schools, and black girls in particular.

Blake sees strict dress codes as a way of targeting certain students without using racial language. By using certain restrictions on hairstyles and dress, school officials are enforcing the policing of black youth.

Toward the end of the school year, the Cook twins, Mya and Deanna, were allowed to participate in their extracurricular activities. That was after much upset from friends and supporters and a word of warning from the Massachusetts attorney general to school leaders at Mystic Valley Regional Charter.

Meanwhile, the Cooks continue to advocate for their daughters as the dress code fight goes on. The school hasn't made any plans, publicly, to change the regulations around hair.

Colleen Cook wants people to know that they're fighting not just for their daughters but for the other black girls in the school who have felt victimized.

Mystic Valley has put out a statement in defense of its dress code policy, stating that the restrictions on hair extensions exist so that the school can promote equity. Hair extensions — it reads — can be expensive.

The Cooks believe this experience has helped them realize the world their daughters have to face.

"When our daughters walk with us, they have our white privilege. When they're not with us, they're black children," says Aaron Cook.

Colleen agrees, adding, "I feel like the school is pushing us to raise them as white children, but that's not who they are or who they're going to be."

The Cooks value their children's black heritage and want them to be proud of themselves at home and at school. They'll continue to fight to make that happen. Copyright 2019 NPR. To see more, visit https://www.npr.org.