I know what you’re thinking, Don’t other animals make tears? Yes, pretty much any creature with eyelids produces them to keep eyes moist and free of dirt. But, although it’s hard to prove, tearing up for emotional reasons seems to be uniquely human.

 

When we’re born, we often wail to attract the attention and care of another person, much like a hungry baby bird calls for its mother to feed it. A few months after birth, babies start to replace loud cries with tears to express a need or emotion. As we grow older, we slowly start to rely on other humans less for survival and more for emotional support. During this time, tears tend to completely replace vocal cries, accompanying complex states of mind like relief, anxiety, frustration, and joy.

 

Why the shift from vocal to tearful crying? One theory is that it allows us to more discreetly direct our desire for support toward specific people. We can avoid attracting the attention of people we don’t find comforting or who might harm us.

 

So the next time your floodgates open, for crying out loud, don’t get down on yourself about it. Remember, tears may have helped early humans survive, and thrive.