There are three types of baby tears, just like adult tears. The types are called basal, reflex, and emotional tears. Basal tears are tears that are always being made to keep the eyes from drying out. Reflex tears are tears that flush out the eyes when they are irritated; think about peeling an onion. The only tears that are associated with crying are emotional tears. These are the most interesting tears because humans are the only animals that seem to have them.
Until your baby learns to talk, crying is your baby’s way of communicating. At first the crying will be dry, because your baby’s tear glands will not be mature enough to produce emotional tears. After the first few weeks, your baby will cry emotional tears to communicate needs like pain, hunger, loneliness, or please change my diaper.
Over time, parents learn why babies cry. They may even learn to interpret different types of crying for different reasons. Since babies can only communicate through crying, it makes sense that the sound of a baby’s cry is a strong trigger for adults, especially parents. Studies show that adults will respond to the sound of a baby crying twice as quickly as any other loud sound. This makes sense from the evolutionary perspective. If parents did not respond quickly to the needs of babies, the species would not last very long. We might have disappeared along with the dinosaurs.
Uniquely human, emotional tears may be the visual component of the evolutionary crying response. Hearing a baby cry triggers us to care and respond quickly, so does seeing a baby’s tears. In fact, the response to emotional tears is so strong that it persists throughout life. Studies show that adults interpret emotional tears as an authentic sign of need. The combination of hearing a plaintive cry and seeing tears well up in another, especially a child, is just irresistible. It can melt the most hard-hearted heart.
Scientists have been trying to figure out why people (including babies) cry emotional tears for years. One clue is that emotional tears are different than basal or reflex tears. They contain stress hormones. It may be that stress, such as the stress of pain or hunger in a baby, triggers parts of the brain that control the tear glands. The release of these hormones into tears may help reduce stress and may be the reason some people feel better after a good cry.
Researchers have also tried to identify the meaning of emotional tears and cries by their characteristics. Here are some examples:
- An angry cry may start with tears pouring out of half-closed eyes and increase gradually in sound and intensity.
- A fearful cry may start with teary eyes open and searching, followed by an explosion of crying.
- A cry of pain may start as a sudden high-pitched cry, like fingernails on a chalk board. Tears will squeeze out from tightly closed eyes.
Other reasons for crying include hunger, colic, loneliness, tiredness, discomfort from being to hot or too cold, irritation from loud noise or bright light, and of course the wet or dirty diaper.
In any case, your baby’s tears mean that your baby needs you. Research shows that babies cry about two hours per day. Parents – myself included – may say that two hours a day must be someone else’s baby. It can seem like an eternity. Crying seems to peak by 6 to 8 weeks and then get a bit better.
For those first few weeks, you may find yourself crying emotional tears of frustration, but when you drag yourself out of bed and see those tears rolling down your child’s face, you have only one possible response, and the species will keep surviving.