[gavinflud]

I had a conversation about this exact thing while on a business trip with some colleagues recently. I'm from Ireland while my colleagues were from Finland, Italy and France. In Irish culture, we talk a lot and seeing strangers conversing on public transport, with the cashier at the check-out or just waiting at a bus stop is quite normal. However, my Italian and Finnish friends said that this was one of the weirdest things they had to get used to when in Ireland. In their respective countries it's just considered common courtesy to not start up conversations with strangers and just grant them their personal space.

This social experiment is very interesting, but the results would probably be very different depending on what country you're in.