Kuba Krys who is a psychologist at the Polish Academy of Sciences had recently published a research paper about “uncertainty avoidance”.
This is the assumption that people from some societies feel anxiety around uncertain situations. The characteristic is found more frequently in politically repressed societies.
It is also found in societies where schooling is respected and structured especially around sciences and where strong social norms are preferred.
Also corruption tends to be more prevalent and civil services tend to be more unstable in these societies.
The paper argued that smiling in such countries would be less welcome – a smiling face could be highly duplicitous.
The study asked thousands of people predominantly from universities in 44 countries to judge eight smiling and non-smiling faces. The results showed that some countries thought you were less intelligent if you smiled such as Russia, Japan and Iran
While some people thought you were less honest like in Argentina, Zimbabwe, Iran and Russia.
Kuba Krys concludes that this “indicates that corruption at the societal level may weaken the meaning of an evolutionary important signal such as smiling”
The study also notes gender and culture play a role and that “the samples may not be fully representative of the cultures they come from “.