Zendaya's high school photo is going viral again nine years after the fact. Over on Twitter, user @khairdoII reposted the stunning pic, which has 79k likes at time of writing. In the comment ...

An analysis of nearly 38,000 American high-school yearbook photos from the 1900s to the 2010s shows the gradual shift from serious to lighthearted expressions, reports Steve Dent for Engadget.