Texas parents are voicing their outrage after their elementary students were subjected to a “segregation experiment” in the name of equity, according to WOAI-TV.

In January, students in a fifth-grade classroom at Leon Springs Elementary in San Antonio were forced to participate in a classroom experiment in which they were separated into groups based on their hair color.

Brandi Lininger told WOAI that students with dark-colored hair “were treated as the privileged ones” while blonde and red-haired students were “treated not so nicely.”