Dogs and rats do it, as do apes. Babies engage in it long before they learn how to speak. For most of us, laughter is a natural response to feeling good and a key component of happiness. Indeed, many of us have probably heard the adage, “Laughter is the best medicine,” and have experienced firsthand the benefits of laughing out loud.

Now, however, scientists are beginning to understand that, when it comes to how our good spirits improve our health, laughter is serious business. In fact, the study of this primal behavior is a valid area of research because laughter has such a significant communicative effect as well as an important social context. After all, laughter crosses all cultural lines, with people across the globe employing the same general sound patterns involving the same regions of the brain to produce those sounds.

In regards to communication, researchers believe that laughter is mostly a response to social cues rather than simply a reaction to a joke. In fact, by some estimates, only 10 to 15% of laughter is attributed to hearing a joke, though it does seem to require the presence of another person. Support for this idea comes from the fact that laughing is not dependent on one single sense, but rather a combination of many senses that culminate in a social interaction. For instance, deaf people laugh without hearing, and people on the telephone laugh without seeing.

And the act is not exclusive to humans. Researchers have observed that chimpanzees laugh when they are tickled by other chimps, and even when that tickling is feigned, suggesting some sort of primal humor. Even rats have been known to laugh when tickled. In fact, they seem to love it, and apparently keep coming back for more.

This phenomenon has even been observed under scientific conditions. Scientists have studied neural responses of laughter in rats as a way to uncover novel and effective methods to treat human illness. Along these lines, researchers have discovered that laughter results in the production of insulin-like growth factors that have anti-depressant and anxiety reducing effects. These growth factors might very well have analogous counterparts in humans.

In light of this, the long-term goal of the research would be to gain a better understanding of laughter’s effect on the human brain in order to create and develop new drugs and therapies to treat depression and anxiety in people.

However, some scientists indicate that laughter, in and of itself, is not as beneficial without the good feelings that normally inspire it. Which kind of makes sense when you realize how good it feels to truly and sincerely laugh out loud. So while laughter might not cure all that ails us, at the very least, it makes us feel better, and that is no laughing matter.