or continue with email
News: The Curiosity Podcast is here! Subscribe on iTunes, Stitcher, Google Play Music, SoundCloud and RSS.
World Smile Day was created in 1999 by Harvey Ball, the man who originated the classic yellow smiley face in 1963. A recent study claims there are 19 different types of smile, including a fake one. How can you spot a fake smile?
Love getting smarter? Sign up to our newsletter and get our best content in your inbox!
Our best articles a few times a week.
You just joined millions of people that love getting smarter every day. Your first email will arrive shortly.