Instructors are people too. Most people are aware of this on a cerebral level by the time they hit high school, of course – it’s pretty obvious that our teachers are not automations that shut down when the final bell rings. But teachers are people too, and they bring with them their biases and preconceptions about the world.
Sometimes, this can be for the better, such as a teacher helping a student deal with difficult circumstances outside of school. But sometimes, this can result in unfair treatment and even bigotry towards different students for a variety of reasons.
Nevertheless, in the face of this sort of situation, you are not powerless. Every student deserves a safe and fair learning environment.
The most important part of dealing with a situation like this is to ensure that you have tangible evidence of unfairness. I trust you, reader, to be able to tell the difference between a genuine slight and your emotions clouding your judgement. But someone who tends to treat people unfairly will not trust you. But if they’re treating you unfairly, chances are good that others are also being treated unfairly. Find them.
For example, if you believe that an instructor is being prejudicial on the basis of gender, talk to other students about it and note both their gender and their response. It’s likely that some of those who are the same gender as you will have also noticed it, and those who are not won’t notice a thing. Both of these pieces of information can be important for proving intent. And now, if nothing else, you have some validation and people you can talk to about it who are going through the same thing.
If they’re being unfair to everybody more or less equally, then it should be trivial to find other students who are willing to back you up. It may be to your advantage to keep a journal of instances of unfairness, and to encourage others to do the same.
Depending on how the unfairness is manifesting, you may decide from there that you want to take action. This can be a scary choice to make in a lot of situations, so it is not one to take lightly, especially if bigotry is involved, as that can increase the risk of backlash.
If you believe that the instructor is just misguided and has good intentions, consider talking to them directly. They may or may not believe you, however, though having the stories of other students will likely help. I would not recommend trying this on an instructor who seems to be deliberately mean, however.
For mea, bigoted, or abusive instructors, it can be a good idea to go over their head. These instructors are unlikely to listen to reason, but if you can prove your case to someone who has superiority over them, there is a greater chance of something being done. In colleges this can be the dean of the department or, in the US, whoever is in charge of enforcing Title IX. In high schools it’s best to aim for the principal. Again, in the US, there’s also the option of taking it to the school board.
Sadly, none of this guarantees that something will get done about it. In some situations, this can even make things worse. I believe it can be worth trying, however. But keep yourself safe first and foremost. There are a lot of structural problems that allow teachers to behave in unfair ways, and you cannot solve them alone.