That book also contains blurbs about elite private day school all over this country; not just those on the east coast; unless the schools mentioned, in Texas, California, and Chicago can somehow be considered to all be on the Atlantic coast.
Sorry I think the attitudes in that handbook about promiscuity and drinking are the same as what you see here in this yearbook. And since I lived it in terms of watching “elite” teens behave like this - I see these types all over this yearbook.