Why Do We Cry When We Laugh?

Have you ever found yourself or witnessed someone laughing to the point of tears? This seems like a conflicting emotional response as tears typically signify sadness, while laughter is an expression of joy. Scientists have not completely pinned down why our bodies produce tears when we laugh too hard, but they have a few theories.

Keeping Up with Your Emotions

Recently, Yale University psychologist, Dr. Oriana R. Aragón, led a research study that evaluated why we experience certain physical reactions to emotional situations. Her team defined these seemingly inappropriate responses (crying while laughing, nervous laughter, etc.) as “dimorphous expressions.” According to Dr. Aragón,  we cry when we laugh so hard because the body is trying to regulate itself in response to strong emotions.

High Emotional Situations and the Brain

Some believe crying while laughing occurs because both reactions are a result of increased  emotion. By crying, the body attempts to return to a regular level of functioning.

Some evidence suggests  the same part of the brain controls both crying and laughing. For example, a condition called the Pseudobulbar affect (PBA) causes people to have uncontrollable outbursts of crying or laughter because of neurological conditions or brain injuries, leading scientists to believe  crying and laughter are run by the same area of the brain.

Under Pressure

Others theorize people cry while laughing because of too much pressure around the tear ducts due to the body shaking during strong laughter. These tears are called reflex tears, which occur when the eyes come in contact with an irritant such as a strong gust of wind or the aroma of a freshly sliced onion. It is important to note these are different from emotional tears, which are produced in response to an experienced emotion, such as sadness or anxiety. 

Benefits of Crying and Laughing

Both crying and laughing have positive emotional benefits. The emotional tears produced from crying are biologically different from other tears our eyes produce. They contain hormones and endorphins in response to stress, which aid in regulating emotions. This is why people say they feel relieved after crying. Similarly, laughter decreases stress hormones and triggers the release of endorphins, which also creates a feel-good effect.

Next time you see someone doubled over from laughter with tears streaming down their face, you’ll know that their eyes are functioning normally. If you or someone you know experience frequent tears that are not related to an emotional reaction, contact The Eye Institute. We can help.