You smile when you’re happy. But can smiling make you happier? Studies have shown that it can. But studies like these are usually enough to make you frown and roll your eyes. Slate’s Daniel Engber traces back a history that will give you sad face.

+ A lightning strike in Norway killed more than 300 reindeer.

+ Vice: Investigating the middle school rumor that Mountain Dew lowers your sperm count. (This is why I only drank Squirt.)