I'm on the fence on the question of walking around being over-smiley.

Temperamentally, I do like to smile and see smiles, but my rational side thinks the Russian view of smiling makes sense.

Seeing people who smile at strangers a lot for no apparent reason as mentally deficient (putting it politely).

Exactamundo!

Thais that work in the tourism industry are not happy.

BUT.. The office workers, and government imployed are perfectly happy.

I think also i have to say..

I used to hate all Thais, because they only cared for the mighty dollar. However this i find out is completly wrong (after living here a few years)!

Its the area you live in that deter if people are generally nice or not.

Currently sitting in my apartment in Ratburana, Bangkok, and here no-one cares about the foreigners at all, and all is super nice and friendly ;-)

if i went to Pattaya/Phuket beach road, i am sure i would feel different..

In my house in Chiang mai, i also feel perfectly relaxed just like here. Never a problem, and people are smiling all day long.

Its due to finances most of the time..