Yearbooks Show That Boomer Students Didn’t Smile for the Camera

Although smiles in yearbooks have generally gotten bigger since the early 1900s, photos of Boomer students actually showed less noticeable smiles from the mid-‘50s to the mid-’70s. Unsurprisingly, the trend towards larger smiles reasserted itself in the mid-’90s, when Millennials first entered high school.

—University of California, Berkeley and Brown Un…