By Allison Ford, DivineCaroline
Crying is an emotional reaction that’s completely unique to humans. Our capacity for complex thoughts and feelings means that we can cry whether we’re overwhelmed with any emotion–happiness, despair, or fear–but not everyone cries the same way or for the same reasons. Some people break into tears at the drop of a hat; others remain stony-faced even when confronted with great tragedy or pain. Understanding the impulse to cry isn’t always easy, but understanding the psychological and evolutionary reasons we do it is even more complicated.
Sad or Hurt, Same Response
All tears are comprised mainly of water, oil, and mucous and are produced in the lachrymal glands near the eyes. Made of the same stuff, we actually have three different kinds of tears: basal, which protect and moisten our eyes; reflex, which flush irritants and foreign objects from our eyes; and emotional tears, which are produced in response to strong emotions or pain. The body automatically produces basal and reflex tears, but emotional tears are only ones produced by the process we think of as crying. Emotional tears have been shown to contain higher levels of certain hormones like prolactin, which is associated with breastfeeding and milk production, and manganese, which helps regulate our moods.
Emotion and pain are both processed in the limbic system, the area of the brain that also processes memories, our senses, and behavior. Humans can cry whether we’re in emotional pain or physical pain, and regardless of the stimulus, the tears are the same. Because of this lack of differentiation, some researchers believe that the body can’t really distinguish between emotional and physical pain at all. Even though the mind knows the difference between a broken heart and a stubbed toe, the body generates the same response to both.