Does the digital world reduce our ability to read the emotions of others?

http://campustechnology.com/articles/2014/08/26/study-digital-media-erodes-ability-to-read-emotional-cues.aspx

"For the study, researchers looked at two groups of students from the same school. The first group, comprising 51 students, attended outdoor school at the Pali Institute, a science and nature camp that doesn't allow student use of electronic devices. The second group, with 54 students, was allowed to use their devices as usual and did not attend the Pali Institute until the study was completed.
Both groups were shown 48 pictures of happy, sad, angry or scared people and asked to identify their emotions, both at the beginning and end of the study. "They also watched videos of actors interacting with one another and were instructed to describe the characters' emotions," according to a news release. "In one scene, students take a test and submit it to their teacher; one of the students is confident and excited, the other is anxious. In another scene, one student is saddened after being excluded from a conversation."
Students who had gone without digital media averaged 14.02 mistakes in the picture test before attending camp. After five days without screens, their scores improved to an average of just 9.41 errors per student. Camping students showed similar improvements on the video test. Students who had not yet attended camp showed a much smaller average improvement on the image test and no change on the video test."

Think of the old days when there were no phones, telegraphs, or fast transportation. What did people do to keep in touch?  Letters.  Sometimes you might get a photo of your loved one included, but usually that was with a stiff non-emotional face because cameras needed you to stay still for a while.  How did people manage to read the emotions of others back then?

I think the better measure would be time spent with actual people, rather than time spent with digital things.