Why we cry
Humans most likely cry to solicit help and comfort, and sometimes to ward off aggression from others (female tears can stop men from being mean). It has these functions in helpless, dependent babies, and we have little reason to assume that this trait changes as people get older.
Why it feels good
It’s possible that there is some physiological benefit to crying, such as stimulation of the parasympathetic nervous system, which is important for relaxation. Shedding tears may also release opioids, natural chemicals that affect our feelings of pleasure, and oxytocin, a hormone linked to bonding, feelings of trust and stress reduction. The largest benefit, however, comes not from crying itself but from the comfort and support others offer in reaction to our tears. All of that said, occasionally controlling your tears isn’t likely to harm your health. But continually suppressing emotions can sap your body of energy and potentially cause physical symptoms.
Why women cry more
First, the male sex hormone testosterone seems to inhibit crying, while the female hormone prolactin may lower the emotional threshold. Plus, women may be exposed to more emotionally charged situations, such as caregiving, and tend to be more empathetic. Finally, men are often expected to control their tears.
Tears of joy—a myth?
Some experts doubt whether we ever cry for positive reasons. Very often, during a happy moment we allow ourselves to reflect on less joyful times. For example, during a reunion, we may actually cry for all the time that we missed each other. And while getting married is often a positive event, at the same time it is the end of a certain phase in life and this could cause tears of sadness. Another theory is that very positive emotions may also evoke a kind of helplessness. You are simply at a loss as to how to express your extreme joy. This inability to adequately convey your feelings might result in tears. — Ad Vingerhoets, Ph.D., clinical professor of clinical psychology at Tilburg University in The Netherlands and editor of Emotion Regulation and Well-Being (Springer)
Why we cry