#152 - The Brain on Music

Matt Walker (0:02)

Hi, there, it's Matt here, and welcome back to the podcast. Today, I'm going to take us beyond the edges of the Sleeping Brain. Let's talk about what the awake brain does everywhere in the world without ever being invited. I'll begin by showing you an object. It is a piece of bone. It's the hollow wing bone of a Griffin vulture, a little longer than your hand. Someone has drilled five small holes along one edge. It was discovered in the floor of a cave in southern Germany under tens of thousands of years of dirt and debris. It's a flute, a proper musical instrument. It was radiocarbon dated to 35,000 years ago, or perhaps earlier. The full archaeological timeline of the cave layers puts the earliest music making in that part of the world at roughly 40,000 years ago.

This bone flute is older than agriculture and older than the wheel.

So here's the question I want to consider tonight, and it's a deceptively simple one. What is music for? Every activity that takes time, every expenditure of energy needs to cover its costs, and anything that can't is jettisoned.

But music, a costly, time-consuming, seemingly pointless activity, has made the cut for 40,000 years across all human groups. Tonight, I'd like to explore what it might be covering. First, let's think about the extent of the data. Make a list of 315 different human cultures and look through the literature for evidence of music. You won't find a single culture that doesn't make music.

A song that serves the same function, a lullaby, a dance song, a healing song, a courtship song, will tend to have the same characteristics in many different cultures. A lullaby sounds like a lullaby almost anywhere on the planet. Within any given culture, there's more musical diversity than between cultures.

No matter where humans travel, music goes with them wearing the same clothes. It appears to be a hardwired capacity. If you play lullabies to infants from cultures they have never heard of, from different languages, different tonalities, their heart rate drops, their eyes relax, their sweat decreases, more than when they hear other songs from other cultures. They can hardly have learned this. Even in the first year of life, the ability is present.

So why evolution built all this? And here's where it gets interesting, is a matter of intense debate. Two competing groups released opposing manifestos a few years ago in the same issue of the same academic journal, which is the closest thing there is in academia to a fistfight. The first group says music evolved as a kind of social glue, a bonding technology that helped humans form groups too large to be maintained by mere grooming and individual friendships. The second group say it started out as a credible signal, an honest advertisement to enemies of how unified a group was, or to an infant of a parent's undivided attention.

Hold both ideas in your mind. The next bit is true for both of them. But there is one thing on which both camps agree, music's natural environment is not headphones. For most of those 40,000 years, music was mostly something done by groups. And when you look at what groups doing music together do to them, the effects are not vague and woo-woo. They're measurable. Take the experiments on silent discos. Get a bunch of strangers to learn some dance moves and give them headphones. Then change one variable, whether they move in time with each other. Move in sync and people's pain thresholds go up. This being the telltale sign that the body has produced endorphins, its own homemade opiates, and they report feeling closer to their fellow dancers. Fail to move in sync and the pain killing effect doesn't happen. Physical exertion does help, but specifically moving together in time has its own unique power. And singing does much the same thing, but very quickly.

Watch the development of groups of newly formed adults doing an education class over seven months, comparing singing classes to craft and creative writing classes. And what you find is the singers bonding much faster and getting closer. It's like an icebreaker, and it works on scale. Check the closeness of members of choirs when they sing in their small groups locally, and then check again when they join a big 232-person choir for a joint rehearsal. In both cases, the session increases pain thresholds and feelings of closeness. You can see it happening even when people are doing nothing more than sitting in an audience. Hook people up to electrodes while they sit at live classical concerts and record heart rate, breathing and the sweat response of the skin. And as the music plays, these individual bodily rhythms begin to synchronize in the room. And the greater the synchronization, the more people report being moved and absorbed by the piece. Multiple experiments with live music have confirmed this. That feeling you get at a gig that the whole room has become one body, you can measure it. And so we come inevitably to the war drum. And if moving in time makes us more unified, then coordinated music is a kind of public statement of our unity. An audible reference check, a crowd that can drum, sing and move together, as one is performing a costly, credible signal of its coordination. Knock the players in a recording 60 milliseconds out of step with each other. And not only does the music receive lower ratings, people's ratings of the music move together with their ratings of the group, making the music, not in lockstep, but a solid, consistent correlation. It is not only the crowd that is impressed. Marching in time changes the marchers.