• Around 50% of people will smile back if you smile at them

 • Smiles are a universal sign of happiness

 • It's physically easier to smile than it is to frown

 • Humans can detect smiles from more than 300 feet away

 • Around 50% of people will smile back if you smile at them

 • Smiles are a universal sign of happiness

 • It's physically easier to smile than it is to frown

 • Humans can detect smiles from more than 300 feet away