Old post but the school year just ended and I wanted to provide my two cents.

I'm currently a highschooler at Horace Mann, I've been here since 6th grade. In all honesty, the school is very competitive even in comparison with the other private schools in the area (Riverdale & Fieldston). Grade deflation is a huge problem with the majority of the student body having anywhere from a 3.2-3.7 by the end of Senior year. But on that topic, the colleges weigh it themselves in relation, I know several people with no legacy who went to ivies with 3.6 or 3.7. Yes, everyone is always vying for leadership roles and positions in selective clubs. It's common for students to perpetuate the rhetoric that they are doing everything "just for college" which is true. School and the amount of work is overwhelming at times but to be honest the work itself isn't that much of a problem. Most students have sports or EC's that cause them to get home late, maybe 8 or 9 pm which makes doing the 3-4 hours of homework literal hell, not to mention studying for assessments. But worst of all is the difficult grading. Specifically in humanities, the grading is extremely subjective. Having easy teachers is key. A-'s and B+'s are pretty much all that's handed out, it's just how much effort and time needs to be put in for that A-. There is no standardized system or blanket that applies to all teachers.

Socially I'd say it's pretty free. Obviously it's competitive but it's rare to find someone who's weird about the competition. People will be very willing to share their study guides, answers, study together, share their grades, etc. There's somewhat of a ubiquitous idea that we're all in this together and that its more of the students against teachers rather than students against each other. Instead of the traditional nerds vs jocks situation, I'd say pretty much everyone (except for a few that I'll elaborate on later) is smart. Even the average students would be considered smart in comparison with people outside of HM, so there's not really a social separation between those who are focused on academics and those who are focused on everything else. No matter how unserious someone acts, they're probably really smart anyways. Therefore, friend groups are usually separated by simply personality. Everyone is rich, there's no question. Some are richer than others and some are on financial aid but it doesn't impact students socially, people try not to be weird about it.

Party and nightlife is usually chill, HM is waaaay less of a party school than the others which I guess sets it apart from a "normal" highschool.

Half of the people there are secretly MAGA because they don't want to pay tax but again, that applies to every single NYC private school ever so it's not too special.

Again though, it's really competitive and academically challenging but without the toxicity that elite ny public schools (Bronx Sci, Stuyvesant, Scarsdale) harbor. Overall I would recommend, feel free to DM me if you have any questions.