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Why Cry?

Wednesday, May 08, 2013 - 04:00 AM

One question that listeners keep shooting our way is why do humans cry? Be it something stuck in our eye, a surge of love, a great joke, a death, or just a crappy Tuesday -- we cry a lot (and when we don’t, the lack of tears is very noticed).

“Tears are really the only bodily fluid that doesn’t offend others,” says Michael Trimble, who we rang up to get the dirty deets on our tear ducts. Trimble is Emeritus Professor in behavioral neurology at the Institute of Neurology, London. He recently wrote a book called Why Humans Like to Cry. What follows is an excerpt of our conversation with Trimble.

RL: What is happening physically when I cry?

MT: If you ask people what’s the opposite of crying they’ll say laughing. The emotion [that comes] with both laughing and crying leads to it being hard to speak -- you get choked. But they are different. Crying begins in the guts; it’s a gut feeling that rises upwards. It starts with heavy breathing, your throat becomes dry, and the muscles around the eye contract. This then triggers a reflex from the central nervous system back to the lachrymal glands with an increased output of tears. You often can’t prevent it. Laughing on the other hand is quite evanescent. And there doesn’t have to be a joke to laugh. For example, “Fred, how are you? Haha,” is used often as a greeting. But crying is usually not a greeting communication. 

That would be a pretty weird way to say hello… in your book, you talk about how humans are the only animals that cry, at pretty much everything. Why do we do it?

Tears have a biological function to make the eye moist. Tears contain proteins and antibiotics to keep the eyes from getting infected. Conjunctivitis, when the eye becomes infected and red, will lead to tears because of the irritation of the eye. If you throw grit into the eye of any animal that has an eye it needs to be kept moist, it will cause tears. But I want to emphasize this: only human beings cry emotionally (but I am not saying that animals don’t have emotions or do not mourn).

Wow, that’s crazy – why are humans the only animals that emotionally cry?

We have no idea precisely. But my [idea] is that when small social communities began to develop language, this allowed for the development of self-consciousness. To be self-conscious, you need the “I,” and to have “I” you need to realize it is “here and now.” With this development, people began to understand that others in their small community died and disappeared. [They began to try to connect to those who were gone, and] this is when early religious ceremonies developed which involved singing and dancing. I believe that this is when crying developed as an emotional signal. Group crying may have been an important aspect of these ceremonies and is still an important feature of religious services today. Over a long period of time my speculation is that the early development of emotional tears happened with bereavement.

Another explanation -- again we can’t prove this -- is that in these early ceremonies, cremation occurred. People were gathered around the fire and that provoked tears through irritation. And then being sad became linked with tears.

But if that was the case, wouldn’t we cry only at funerals? But we’ll cry at pretty much any emotion…

Well, it’s linked to loss and detachment. The most important things to mammals are mothers. If the mammal infant does not cry out, it will die. The separation call is the first thing that happens; it’s the beginning of bonding a baby to a mother. In my opinion, this is why we generally feel better after crying -- because it’s an emotional response learned early on. And this developed between one million and 200,000 years ago, [though] we can’t be very exact.

So you’re saying that crying makes us feel better because it reminds us of being comforted by our mothers, but then I saw some studies arguing just the opposite. Is crying really good for us? Most people generally say it makes them feel better.

The majority of studies indicate that people feel better after crying. It’s situation specific -- obviously if you have a domestic argument and it continues, you won’t feel any better. But with music, poetry, bereavement… you feel better. In fact, crying is [often socially] expected. Shakespeare had a great quote about this:

And if the boy have not a woman’s gift  

To rain a shower of commanded tears,

An onion will do well for such a shift.

Are you saying that Shakespeare was all about shoving an onion up our sleeves to make us cry when necessary?

What it comes back to is catharsis, an Aristotelian idea, which goes back to the theater of tragedy. Tragedy, particularly if combined with music (for example opera or the movies) leads to an emotional response which is positive, interlinked with this is very often crying. [Under the right circumstances,] the sensation of feeling better is prolonged with crying. When you laugh, the feelings are very often over as soon as the laughing bout ceases. If you go to an opera and cry at the death of Mimi [in La Boheme], your calmness lasts much longer.

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Comments [13]

Linda Wilson from Gunnison,Co.

I have a mule named Jill that I rescued along with her friend Sweet Pea. Their ages were unknown--but it was obvious they had been together for many years. When Sweet Pea died last fall Jill was very upset and several times throughout the day she was seen with tears rolling down her face. ps she has a new friend now named Muddy.

Jun. 15 2013 08:16 PM
Ann Poland from USA

Babies cry because they come into the world being able to cry. They learn not to cry by well-meaning adults whose ability to cry was also interfered with. If a child was allowed to cry, he/she would cry at any incident which made this individual sad, or mad or hurt or very happy. Our society has it backwards. Crying is the healing of our hurt. We came knowing how to heal ourselves.

For instance, let us say that there is a one-year old who is learning to walk. The child toddles along and falls over a toy on the floor. The child, feeling something, begins to cry. The relaxed adult in the room goes to the child, sits down beside him/her and just warmly smiles at the child, maybe puts a hand on the child's shoulder. Depending on just what did go on, the child will sit and cry until the hurt, fear, anger, pain — whichever it is, is gone and then gets up and goes about the business at hand. If the hurt was terror, the child will grab the adult and bury its nose in the neck of the adult and sob and sob and sob until the terror has been discharged. The marvelous thing about this is that there will be no mis-storage of the hurt. If allowed to discharge, the child will not have any residue from this hurt that was just experienced.

May. 27 2013 05:54 AM
Brian from Portland, OR

What do we know about the structures in the adult brain that allow us to cry? Crying was something that used to happen to me every few months, but since a brain injury when I was 24 I have been unable to cry.

May. 21 2013 05:53 PM

Born to Cry - Chelsea interestingly raised the adult vs baby question. The cry coming forth from the vocal cords of a newborn is the infant's lifeline. At that stage it's rarely accompanied by tears. 'I'm here and will not be ignored,' cries the newborn. Researchers have found evidence of a change in the structure of the vocal folds in the first few months from a more uniform tissue, possibly devoted to the singular task of demanding attention, to a differentiated layered structure allowing for nuanced communication.

From an article by Drs. Schweinfurth and Thibeault on the crying of newborns (adult vs baby):

"A healthy adult has difficulty sustaining submaximal phonation at 85 dB for over 20 minutes without developing dysphonia and stroboscopic changes.. However, it is not unusual for a child to sustain peak or near-peak volume for over 3 hours. ... Despite long periods of sustained, near-maximum levels of pitch and loudness, the pediatric larynx is evidently more resistant to the downward progressive spiral of increasing effort, edema, and subsequent aphonia that occurs in adults." (Schweinfurth JM, Thibeault SL, Does hyaluronic acid distribution in the larynx relate to the newborn's capacity for crying? Laryngoscope 2008 Sep;118(9) p 1693)

It would also be interesting to see if there was some correlation between emotional tearing and the development of vocal function, or even with the loss of that function altogether.

May. 21 2013 01:31 PM
megan from Phoenix

I'm sorry but this article doesn't really add up. I feel like it is missing a paragraph or two. There are many good points in this article. However, infants have never seen their mother cry and many infants do not have mothers but they still cry, not just shout for help but cry tears. From the way Trimble discusses the evolution of crying he makes it out as a learned behavior. It just doesn't make logical sense. But then again I have not read all the literature...

May. 17 2013 06:37 PM
WhatAGal

Great article as usual. Although I probably shouldn't have read this while also watching the ending of Marley & Me...

May. 13 2013 02:30 PM
Bill

I was shocked to read this article and see such an absolute claim that only humans emotionally cry posted here. This, especially when Radiolab did such an excellent job exploring the issue of animal emotions with their Laughter program (i.e. the laughing rats).
A more accurate statement might be that while there have been scattered, anecdotal claims that elephants and various primates also shed tears emotionally, none of those claims have been scientifically verified.

May. 11 2013 09:31 AM
Chelsea

I wonder how linked to our later emotional crying as adults is related to our crying out as babies. It's a highly conserved behavior throughout development, although it does take on a more emotional, self awareness later in development.

May. 08 2013 07:23 PM
Anna Bleekz from San Francisco

Awesome article, yo. I always just kinda assumed that crying was an evolutionary artifact of baby-crying--which, as you mentioned, is useful for mom-baby interactions. Never thought about the whole tears side of things.

Oh man. Dat post-cry feeling you described. Now I want to cry.

May. 08 2013 05:51 PM
Libby L from New York

When Elephants Weep by Jeffrey Masson is also a good read about emotions in animals and how elephants are also known to grieve with tears.

May. 08 2013 11:37 AM
Anna

I thought, unlike reflex tears, emotional tears contain manganese, prolactin, and cortisol? This would be evidence that emotional tears relieve the body of high (potentially toxic)levels of stress relieving hormones.

May. 08 2013 11:08 AM
dianea kohl from ithaca, ny

As a psychotheraapist, I have been on my own crying journey of healing into true love since the early nineties...which has relieved me of anger and brought and brought a heart opening bigger than ever though possible...even bodily symptoms disappear!
check our my CRYING books and website at www.makereallove.com

May. 08 2013 11:03 AM
bold

I wonder if you guys have seen the documentary titled "The Story of the Weeping Camel." It shows that camels do cry emotionally. Please give this film a try. It is really good.

May. 08 2013 10:32 AM

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