The more open attitude you described seems to be on an upward trend in the generations born in the ’80s and beyond, but by and large we Americans do not talk money except with the closest family and of course one’s professionals. Even asking how much someone paid for a big-ticket purchase such as a house, car, horse, land, etc. is considered rude. I wouldn’t ask about something as small as a TV. Even verbalizing that someone is better off or little comments like “no big deal because they’re rich” is awkward for at least a couple of reasons: it leaves the “complimented” person feeling a little embarrassed and then also wondering why the other person is thinking about someone else’s finances.

My parents don’t know my income. My siblings don’t. I know a good bit about my mother-in-law’s income and net worth, but it’s because she is single and has asked for specific financial advice. My parents have recently been going through estate planning paperwork, and I suspect we may have discussions about finances in the next few years.

There are of course exceptions. Within niche hobbies, people may be a little more open after they know each other well about how much goods and services cost, but still not about income. A n00b walking up asking those sorts of questions may still get pushback — depends on how he asked.

I’m on the senior management team for a small technology company, but even though we can all see everything, we don’t discuss each other’s compensation directly and sort of pretend not to know.

The stereotype is definitely incorrect. Americans find it incredibly uncomfortable to talk salary. It's considered pretty rude to ask, if someone's going to, it's usually preceded with an apology or a 'if you don't mind me asking'.

No, that's very wrong. Talking about salary or really money in general is rude and kind of unseemly. You generally would never ask someone how much they make in social situations, and only assholes would brag about their salary to others.