According to linguists, the term Carioca, as locals call themselves, is not derived from the word Rio, as in carioca. It is actually a Tupi Indian term (kara’i oca), roughly meaning “white house”, or “house of whites”. That’s how they called the houses built by the Portuguese. For some reason, eventually the Portuguese started thinking of themselves as Cariocas.
You don’t have to be born in Rio to be a Carioca. All you have to do is relax into the city lifestyle, and soon you will become one. There are some basics you should learn first, though, if you want to make friends with locals, that is.
The most important is that time is a flexible concept in Rio. Unless you are talking business meetings, half an hour late means perfectly on time. If you don’t understand this, you will live on the verge of a nervous breakdown while in the city, sure that everybody is trying to leave you behind.
There’s another trait that is hard for visitors to figure out. Cariocas are a friendly breed, and they don’t mind engaging in a conversation with perfect strangers. But when a Carioca says something like “I’ll call you later”, “Call me later”, “Show up at my place”, or “I’ll meet you at the club tonight” they don’t necessarily mean it. Maybe they’re just being polite. Another Carioca wouldn’t give it a second thought. But if you’re an out-of-towner and it happens to you, it can be quite frustrating. Just don’t take it personally, and always keep a Plan B.