The Science of Crying

• Some ludicrous theories are that humans evolved from aquatic apes and tears helped humans to live in saltwater.
• Others persist that crying removes toxic substances from the blood that builds up during times of stress.
• More plausible theories are that tears trigger social bonding and human connection.
• Crying signals that there's some important problem that is at least temporarily beyond your ability to cope.
• Tears show others that we're vulnerable, which is critical to human connection.
• Crying is also used in manipulating others.

Researchers found that non-crying people had a tendency to withdraw and described their relationships as less connected. They also experienced more negative and aggressive feelings like rage, anger, and disgust.

There is no evidence that crying comes with any positive effects on health. There is also no evidence that holding back tears would have a negative effect on the mind and body.