system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why do we produce tears when we are sad?
gpt
Emotional tears are different from reflexive tears (tears that come from smokey rooms, cutting onions, etc.). When you cry because emotions, it releases a hormone that causes you to feel less stressed after you have cried. This is also why we cry when we are in pain or extremely frustrated.

There are also some evolutionary psychologists who think that emotional tears gave our predecessors a leg up, as it served as a cue when somebody was emotionally distraught. This would help the tribe quickly identify somebody who was in need and help them out however they needed.