How has the photo of the student record changed over the last 100 years?

Watch the change in the faces of students in the yearbook through every decade.

The change of the yearbook image over a century

If you've ever seen portraits before, many will realize that the old people rarely smile. So for the photos of the yearbook of students in ancient times?

Researchers at the University of California, Berkeley recently scoured yearbook photo books in high schools to find answers to the question: "The yearbook of students over the past 100 years has replaced How to change? "

Shiry Ginosar, the leader of the research team, began downloading 150,000 scanned portraits by school libraries in the US, starting with photographs taken at the time of 1905. This group used algorithms to filter all the unnecessary information in the photo and just taking each person's face, they finally collected a total of 37,000 photos in 800 yearbook books from 26 US states.

In the end, they group all the images over the decades and use the algorithm to process the "common face" for each decade. Below is a summary of the year-round portraits that can be seen by these students' smiles :

In addition, this group also summarizes the yearbook portrait of female students through the decades:

As you can see, even the portraits of men and women have changed, from smiles in the 1900s to laughing at the 2010s.

In addition, this study also adds to the conclusion that female students laugh more than boys in year-end photographs over the decades.