The following did not come out as well as I had hoped...Oh well:
High School was definitely a brainwashing factory. There is no way that place conveniently got stuck in my subconscious without any "professional" effort involved.
When I was in 11th grade my classmates and I were having a discussion on kollel at the shul (where we had lunch) and in entered a classmate and close friend of ours Ariella (name changed to protect identity). Ariella joined into our conversation and said "How could you guys not want learners, do you want your husbands to abuse you?"After the initial shock wore off we all attacked her. We argued "Ariella, just because a guy is a full-time learner doesn't mean he has less chances of beating his wife." To that she had nothing to answer but "Kollel husbands learn how to treat their wives properly by learning Torah, the other guys do not learn such things." So we replied with "Yes, but guys that work and learn as well, treat their wives just as nicely. Guys with morals, without Torah, do so as well." Conversation ended there.
Also, once in 9th grade, I brought in my 8th grade year book from public school. A bunch of my new friends surrounded it so that I can show them my crush (this was during lunch, so no teachers around). A few girls that were on the "frummer" side also wanted to take a look, and one girl said "wow, that's so scary, did you like, ever see a gun?" I had no idea what to answer her, but I said "no, that's not as common as you'd like to think"
Then of course there was the time I said something that was obviously right out of frumville but thank goodness I was able to yell at myself after that!
Anyway, if you think these situations are just "coincidences" I urge you to think otherwise. I assure you that my school (as well as many B"Y) really do brainwash people. Here are the ways I think they get us.
Firstly, my HS had uniform. Uniforms as convenient as they are in preventing peer pressure, and the "I have nothing to wear" stress of the mornings, are really just a tool used to conform all the girls, especially true of the HS I went too.
Our HS did not just have a uniform in which we had to wear a specific blouse and a specific skirt, but we had a SPECIFIC rule for which COLOR socks and shoes we can wear. We also were not allowed to wear any "loud" jewelry or dangly earrings. Nor were we allowed to wear our hair down. We had to have our shirts tucked in. In the winter we were not allowed to wear boots once inside the school. The uniform was strict as well as strictly enforced.
"What you choose to wear says something about who you are"
After years of wearing a uniform in elementary school (like most girls had done prior to entering HS) plus the even stricter uniform of HS leaves little room for individuality, or the ability to have it really reflect "who you are", in fact, the reverse usually happens, in that the girls tend to change themselves and reflect what the uniform wants them to be. And that is why they have cases of girls believing their husbands will beat them if they do not learn full-time (which is a symbol of conformity in today's society).
One of the years that I was in the school 2 girls got kicked out because they were caught, in Florida, on a beach wearing bikini's. Basically, not only do the girls have to abide by uniform while they are in it (which even I cannot argue that) but they have too when they are hundreds of miles away, in a different state. I understand if they wore bikini's made out of the same pattern as our uniform skirt was. But this is ridiculous. This is the extent of the control.
Aside from the strictness of uniform, I believe the narrow-mindedness applied when hiring faculty shows the brainwashing of the school.
The school did not allow any non-frum teachers. They did not allow any teachers to be "more modern" than that of the school. Often times in class we would discuss chulent recipes, and dating, and "views on pledge of allegiance" with teachers that taught secular subjects!! Its like , fine, when learning halacha we can discuss shabbos recipes, but with the math, history, or science teachers, is that normal? Ofcourse, because your entire school teaches that if you do not eat gefilte fish, its "bad for shidduchim" if you do not conform, your kids will be more likely to go off the derech. Its almost like they care more about their stupid pettiness than they do about TRUE Judaism. Its like, they somehow care more about the ridiculous baseless chumras and minhaggim then they do common sense, truth, and happiness. You want your kid to be a dumb idiot, or allow him to decide for himself? How likely is it that a BY teacher will tell you "decide for himself?"
Oh. Then there's the time my teacher told me that I was too stubborn to be able to get married. So I was like "no, I'm just too stubborn for the average guy, but I don't want average. I want a guy that is argumentative and wouldn't mind an argument or two himself." And she says "Guys like that do not want to argue with girls" Now, aside from the fact that LITERALLY my entire family is loud, stubborn, and argumentative, I found that hard to believe, because they're all married (rather interesting marriages, but lasting). But my teacher was literally telling me that guys don't like stubbornness, and girls have to be "calm, nice, agreeable, etc." (Many girls attacked her for this, but I forgot what traits she got them on). She literally believed this, and a few of my personal friends literally kept their mouths shut while dating because they feared the guy would not want them. (one friend had an entire dream of being a stay-at-home mom, once married she's going for a masters because "he wants me to work", I asked if she even discussed it on dates, and she says "it didn't come up" I find that hard to believe that career goals NEVER found a way into any of their convo's).
Also, there's the time they planned a Lakewood shabbaton (I did not go, I am terribly anti this kollel nonsense), but that Monday the girls came back singing "We can, We can, We Can, We can support our men" And ofcourse they all agree to become professionals, mothers, caretakers (aka slaves) in the name of "Torah learning"
If uniform in clothing, and uniform in faculty don't do it, I don't know what does. But my school definitely brainwashed us. And all that stuff above is just my speculation on how.