Russia's President Putin is more known for his scowls than his smiles
On a Russian coach, tour guide Tatyana points out the sights of Moscow to a group of American tourists.
Tatyana's big on facts - she has rattled off enough of them to fill an encyclopedia. What she is short on, though, is emotion.
Tatyana has not smiled once. Her audience isn't too surprised - they haven't seen anyone grinning in Russia all week.
"Look at their faces, they're all grim-faced people," complains Bernie. "There's not a person who seems happy and cheerful."
"If you smile, they'll frown" explains Karen, "because they'll assume that if you're smiling you must have an ulterior motive."
Russians do not deny they smile less - but they say their smiles are worth so much more.
"In Russia we have a saying," Professor Svetlana Ter-Minasova told me. "Smiling without a reason is a sign that you're crazy."
'Service with a scowl'
Professor Ter-Minasova is a specialist in Slavic smiles at Moscow University. Russians, she claims, will only smile at you when they really mean it.
And that makes them more sincere.
"Americans overdo it. They smile at every step and for them a smile is a sigh of prosperity. But a smile is more precious in a nation where people don't smile so eagerly and so automatically."
If there is one thing smiles are not in Russia, it's automatic.
Whether you're dealing with border guards or bank clerks, shop assistants or hairdressers, it's more likely to be service with a scowl.
Don't take it personally, though. Not smiling has become Russians' defence mechanism.
"People's behaviour is a way of protecting themselves in hard surroundings, where government has never been friendly to people," says Russian broadcaster Vladimir Solovyov.
"It's their protection, their castle, it's why they don't smile.
"Because they don't know, maybe you are an enemy, maybe you are the person who will go to the KGB and tell them you've misbehaved."
Smile of satisfaction
Things are slowly changing as Russians cotton on to the commercial benefits of being nice.
Ever felt you're not welcome?
The Russian airline Aeroflot has been training its cabin staff to be more smiley and polite to passengers; even the state border guards have been ordered to grin so that tourists aren't scared to come here.
But Markus Luken, Human Resources Manager for Ikea in Russia believes that if Russians don't want to smile, you can't make them.
"You cannot force people to smile. People have to smile because they are satisfied with their jobs, their lives, their performance.
"Then they will smile automatically."
Back on the bus, Tatyana's still going strong, and still looking very serious.
Furrowed brow, no time for chit-chat or chuckles.
And yet by the end of the tour, this grey figure has won me over - in a world where the "Have a nice day" culture has mushroomed out of control, there's something so refreshing about somone who doesn't smile.