Speech as Byproduct

Jonathan L. Friedmann, Ph.D.

Human beings like to celebrate the uniqueness of our species. Of all the terrestrial creatures, we are the ones who have built civilizations, developed science and technology, invented philosophy and sport, produced art and medicine. Exactly how we attained the presumed mantle of superiority is not as clear. The usual list of explanations leads us to similarities with other animals, rather than to exclusively human traits.

For instance, our “big brains” have roughly the same brain-to-body mass ratio as mice, and are outsized by dolphins and some small birds. Tool use is present among various animals, including primates, elephants, ants, wasps, certain birds and some octopi. We share an opposable thumb with koalas, opossums, several primates, certain frogs, and a few dinosaurs. We are not the only animals to walk on two legs—just look at any bird. Even the gene largely responsible for language (FOXP2) is found in other species, like chimpanzees and songbirds, albeit in different variants.

It could be that what makes us human is not one of these traits, but all of them in combination. For example, the anatomical emergence of the opposable thumb facilitated tool culture, and large brains enabled the development of seemingly endless devices, including written language. Indeed, many scientists contend that language advancement—built from the convergence of other human characteristics—is what makes us unique.

Dr. Charles Limb recently challenged this conventional view. Limb, an otolaryngological surgeon and saxophonist, was intrigued by musical conversations that take place between improvising jazz players. Using an MRI machine, he and a team of researchers mapped the “jazz brain.” First, they instructed a musician to play a memorized piece of music. Next, they asked him to improvise with another musician, who played in another room. Their findings show that collaborative improvisation stimulates robust activity in brain areas traditionally linked with spoken language. Moreover, it appears that the uninhibitedness and spontaneity of improvisation is closer to a dream state than to self-conscious conversation.

As a mode of communication, music is more complex and intuitive than the comparatively straightforward systems of verbal and written language. For jazz improvisers, the back-and-forth is both plainly understood and impossible to put into words. The fact that the brain can process this acoustic information, which is far more complicated than speech, suggests that musical capacity—not language—is the distinctive human-identifying trait.

To be sure, “musicality” is also present in songbirds, whales and a handful of other animals. But the complexity of music perception in humans is so advanced that modern science cannot fully comprehend it. Limb says it best: “If the brain evolved for the purpose of speech, it’s odd that it evolved to a capacity way beyond speech. So a brain that evolved to handle musical communication—there has to be a relationship between the two. I have reason to suspect that the auditory brain may have been designed to hear music and speech is a happy byproduct.”

Visit Jonathan’s website to keep up on his latest endeavors, browse his book and article archives, and listen to sample compositions.