With just a smile in the mirror, a casual pose and the flash of a phone camera, a selfie is made and shown to all of an Instagram user's followers. This photo receives the most 'likes' and engagement on social media, - and there is science behind it.

According to a Georgia Institute of Technology study, the reasoning is simple: We love faces.

In over 1.1 million photographs on Instagram, pictures with human faces were 38 percent more likely to receive likes than a photo without a face. In addition, these photographs were also 32 percent more likely to attract comments, according to the Epoch Times.

"Even as babies, people love to look at faces," said Saeideh Bakhshi, who led the study.

"Faces are powerful channels of non-verbal communication. We constantly monitor them for a variety of contexts, including attractiveness, emotions, and identity."

This scientific finding could mean more than just added followers. According to study advisor Eric Gilbert, social media marketing tactics could be improved by adding faces and would keep social consumers active.

"Designers could also use this knowledge to quickly filter, prioritize, and highlight photos shared by followers," Gilbert said.

"Especially pictures that have just been submitted and haven't had enough time to pick up very many likes or comments yet," he added.

Perhaps this is why Ellen DeGeneres had the most retweeted photograph of all time, with the faces of Bradley Cooper, Jennifer Lawrence, Brad Pitt and other Oscar winners. The photograph was eventually revealed as a paid product placement by Samsung.

In addition to the selfie, the study found that popularity in posts also depended on the amount of followers and how often the user created posts, according to the Epoch Times.

Team members of the study also hope to continue their research to see the popularity of photographs with friends in comparison to photographs including family members.