LifestyleWhy Tears are a Scientific MysteryTo view this video please enable JavaScript, and consider upgrading to a web browser that supports HTML5 videoLifestyle02/20/2014February 20, 2014We don't only cry when we're sad. We also shed tears when we're in pain, angry, or deeply moved. In these cases, it's not obvious what purpose tears serve - but there are plenty of theories.https://p.dw.com/p/1BBqjAdvertisement