Analysis of information sources in references of the Wikipedia article "Harvey Ball" in English language version.
A Swedish study found that it is indeed difficult to keep a long face when you look at people who are smiling at you. Smiling is just contagious! Seeing people smile stimulates our mirror neurones to suppress our facial muscle control, and trigger a smile. 'You smile, I smile' is actually a scientific fact!
In fact, the commonly known smiley face is considered a symbol of goodwill and good cheer on our planet; an international icon.
{{cite news}}: CS1 maint: bot: original URL status unknown (link)A Swedish study found that it is indeed difficult to keep a long face when you look at people who are smiling at you. Smiling is just contagious! Seeing people smile stimulates our mirror neurones to suppress our facial muscle control, and trigger a smile. 'You smile, I smile' is actually a scientific fact!