In Steven Mithen's imagination, the small band of Neanderthals gathered 50,000 years ago around the caves of Le Moustier, in what is now the Dordogne region of France, were butchering carcasses, scraping skins, shaping ax heads -- and singing.
One of the fur-clad men started it, a rhythmic sound with rising and falling pitch, and others picked it up, indicating their willingness to cooperate both in the moment and in the future, when the group would have to hunt or fend off predators. The music promoted "a sense of we-ness, of being together in the same situation facing the same problems," suggests Prof. Mithen, an archaeologist at England's Reading University. Music, he says, creates "a social rather than a merely individual identity." And that may solve a longstanding mystery.
Music gives biologists fits. Its ubiquity in human cultures, and strong evidence that the brain comes preloaded with musical circuits, suggest that music is as much a product of human evolution as, say, thumbs. But that raises the question of what music is for. Back in 1871, Darwin speculated that human music, like bird songs, attracts mates. Or, as he put it, prelinguistic human ancestors tried "to charm each other with musical notes and rhythm."
Some scientists today share that view. "Music was shaped by sexual selection to function mostly as a courtship display," Geoffrey Miller, of the University of New Mexico, argued in a 2001 paper. But like Darwin, he bases that conclusion on the belief that music has "no identifiable survival benefits." If a trait doesn't help creatures survive, then it can persist generation after generation only if it helps them reproduce.
Studies in neuroscience and anthropology, however, suggest that music did help human ancestors survive, particularly before language. In "The Singing Neanderthals," which Harvard University Press is publishing Friday, Prof. Mithen weaves those studies into an intriguing argument that "language may have been built on the neural underpinnings of music."
He starts with evidence that music is not merely a side effect of intelligence and language, as some argue. Instead, recent discoveries suggest that music lays sole claim to specific neural real estate. Consider musical savants. Although learning-disabled or retarded, they have astounding musical abilities. One savant could hardly speak or understand words, yet he played flawlessly a simple piano melody from memory despite hearing it only once. In an encore, he added left-hand chords and transposed it into a minor key.
"Music," says Prof. Mithen, "can exist within the brain in the absence of language," a sign that the two evolved independently. And since language impairment does not wipe out musical ability, the latter "must have a longer evolutionary history."
In the opposite of musical savantism, people with "amusia" can't perceive changes in rhythm, identify melodies they've heard before or recognize changes in pitch. Since they have normal hearing and language, the problem must lie in brain circuits that are music-specific.
More evidence that the brain has dedicated, inborn musical circuits is that even babies have musical preferences, finds Sandra Trehub of the University of Toronto. They listen longer to perfect fifths and perfect fourths, and look pained by minor thirds.
If music is indeed an innate, stand-alone adaptation, then evolution could have nursed it along over the eons only if it helped early humans survive. It did so, Prof. Mithen suggests, because "if music is about anything, it is about expressing and inducing emotion."
Particular notes elicit the same emotions from most people, regardless of culture, studies suggest. A major third (prominent in Beethoven's "Ode to Joy") sounds happy; a minor third (as in the gloomy first movements of Mahler's Fifth) provokes feelings of sadness and even doom. A major seventh expresses aspiration. The absence of a third seems unresolved, loose, as if hanging, adds jazz guitarist Michael Rood, 17 years old.
The fact that listeners hear the same emotion in a given musical score is something a Neanderthal crooner might have exploited. Music can manipulate people's emotional states (think of liturgical music, martial music or workplace music). Happy people are more cooperative and creative. By fostering cooperation and creativity among bands of early, prelanguage human ancestors, music would have given them a survival edge. "If you can manipulate other people's emotions," says Prof. Mithen, "you have an advantage."
Music also promotes social bonding, which was crucial when humans were more often hunted than hunter and finding food was no walk on the savannah. Proto-music "became a communication system" for "the expression of emotion and the forging of group identities," argues Prof. Mithen.
Because music has grammar-like qualities such as recursion, it might have served an even greater function. With music in the brain, early humans had the neural foundation for the development of what most distinguishes us from other animals: symbolic thought and language.