Regardless of whether you are male or female, half of your ancestors (descendants ) were ( will be ) male and half female. Why should you be more offended today when one gender was historically repressed because of your gender today?

[Visiting an art museum, the docent leading the student group noted that women at some point in history had to pretend to be men to be allowed to paint. This was intended to guilt the boys in the class]

@Transportist was it intended to guilt the boys or to give perspective on how pervasive differences in the access to opportunities can be? I'd say that's a good hook to mention that many groups (often women) have far less rights than other groups in a great deal of countries. That's also an important thing to understand why you basically don't hear about prominent women (or any minority) in history in many places/areas of interest.
@pedrocamargo I'm sure they would defend themselves by saying something like that, but delivered to a group of boys it's designed to make them feel bad (I'm sorry "reflect") about things they did not and would not themselves do. (Being boys, they probably ignored it.) Bringing up grievances about past crimes, over which those being taught the lesson are powerless, is not a way to move towards equality, it just hardens and deepens divisions. Equality does not require trying to make boys feel bad.

@Transportist I could not disagree more. This: "... grievances about past crimes, over which those being taught the lesson are powerless... " is basically asking to not teach history. I can agree that there is a question of age appropriateness, but it is a fact that the African slave trade is directly responsible for the AVERAGE lower social status that black Americans experience when compared to white Americans. Should we not teach about the slave trade or about cause and consequence to preserve white kids' feelings?

Further, asserting that this is designed to achieve a certain objective (i.e. Making the boys feel guilty) gives you the burden of proof. Since you acknowledge that such assertion would be repudiated tells me you can't prove your assertion, making it almost a requirement to dismiss it.