I had a good friend in HS who had two older brothers and her parents flat out told her that they didn't expect her to do well in school because she was a girl!!!! C's with the occasional B or D were just fine. Grrrr. The only academic class that we were in together was American History and I made her study with me as much as possible for tests. (Looking back, I must have been really bossy!!!) When she'd study, it was straight B's, with the occasional A. So she had the ability to do better, she just didn't bother trying. This was in the 70s, by the way.