When Hubby visited Ukraine, he had to wait several hours in the Frankfurt, Germany, airport, both coming and going. While he was sitting in the waiting room, he noticed that the German travelers kept to themselves, and didn't chat with other travelers. He said that the only Germans who chatted were family members who chatted a little bit among themselves. He could tell which travelers were Americans. They started conversations with people sitting next to them or across from them. They also chatted with people while waiting in lines.
He said the only smiling and friendly people in Germany and Ukraine were service industry people--that is, waiters, waitresses, airport desk clerks, shop keepers, etc. Ordinary people on the street, in the airports, in parks, etc., were not friendly. Whenever anyone in his visitor group tried to be friendly with Germans or Ukrainians, they were either ignored or looked at suspiciously. Hubby said it was a spooky feeling.
It wasn't just the language difference because some people in his group were bilingual. Also, smiles don't require language.
Hubby said when he visited Italy and Spain, Italians (except in the restaurants) weren't friendly but Spaniards were very friendly.
When Hubby visited Guam, the Philippines, and Japan, he said that the Japanese (except in the service industries) weren't friendly, some Filipinos were friendly, some not, and the Guamanians were mostly friendly.
That doesn't mean they are bad people; it just means that their culture is different.