One of my favorite “weird things” in Brazil is the fact that the “thumbs up” gesture is completely socially acceptable, and used for everything. It is the appropriate response to “Does anyone want a beer?” and “What’s up?” It can also mean “thank you,” “you’re welcome” or “I’m sorry.” Brazilians don’t ever use it sarcastically. Instead, they make the thumbs up look like a normal, everyday gesture.
I’ve tried to explain to my Brazilian friends that in America it’s more of a goofy-dad gesture that goes along with “Good job, kiddo!” but the truth is, I love this. I’ve said before that I feel a bit like a kid here (less so now, with my portuguese improving), and constantly getting thumbs-ups from my friends subconsciously makes me feel reassured, like I’m doing a good job.
And honestly, I’ve now become so adjusted to it that I’ve begun to overuse it myself. I tend to make a lot of gestures when speaking English with Brazilians to help myself be understood (or perhaps because many Brazilians are part Italian), and throw in a thumbs up at the end when I ask “got it?”
And of course, they respond with a thumbs up.