It's one of my favorite things about living in a suburban area. Someone will drive down the block, or be walking by, and I legit have no idea who the hell they are as I'm not super neighborly - but I'll still do the little head nod thing and the half wave, and they see it and do it back, and it's just a nice little way of saying "hi, yes, we're in each other's extended personal spaces but have no plans on murdering one another - have a pleasant day."
I heard a theory somewhere that the last Neanderthals bred themselves into extinction because male Neanderthals would be more favorable for female Homo Sapiens; female Neanderthals and male Homo Sapiens that couldn't find mates would find each other more favorable than not mating.
It's a weird thought. Not sure how true it is either.
When I was visiting Hiroshima Japan we took a boat out to Miajima (an island). I was standing on the back of the boat and saw a similar boat bringing tourists back. I started to frantically wave and eventually the other boat waved back.
This is like when the Queen was at a livestock show and they brought in some cows. She leaned toward Prince Phillip, pointed at the cows, and said, “Cows!” Why? Because there were cows, I guess.
As an aircraft crew member, I can confirm: it is all vehicle types, it can be initiated by the vehicle or the ground person, and we all love it. Not really sure about the community size, it's not like I've ever known anyone I waved at.
Yeah but your examples are members of the same community. What is weird and endearing is that people who have never been on a boat will wave at people just because they are on a boat. Conversely, people on a boat will eave at people on land. Its as if a transport vehicle was a ride. A jet ski or something.