Delight, glee, euphoria —all these positive emotions fall under the happiness umbrella,". Which means that if you can spot a true smile, you'll have the general idea. Look for the Duchenne smile—corners of the lips turned up, cheeks pulled higher, skin around the eyes crinkled. "People can try to fake the crinkly skin around the eyes, but it will look strange and squinty, not happy," Frank says.