Why do we dance?
We know what looks good when we’re watching dancers, but why do we bother doing it in the first place? Where did it come from and how linked is it to music? Georgia Mills spoke to Ian Cross, Professor of Music at Cambridge University to learn about the evolution of dance...
Ian - Probably the same reason that language evolved: to enable us to engage with each other, and primarily to engage with each other socially.
Georgia - Do we know when it came?
Ian - No, we really don’t. It’s unlikely to have happened before we became particularly bipedals, so it’s going to be post-australopithecine.
Georgia - I do like the idea of apes in trees sort of jigging around.
Ian - Well, interesting you should say that. Until a couple of years ago, I didn’t really believe any of the evidence that suggested that chimpanzees could keep in time with each other until I saw some material from the Kyoto Primate Lab in Japan, which showed pretty unambiguously that chimps can tap along in time with each other. In other words, chimps could do something like dance with each other but, only if they’re good mates or they’re related.
Georgia - Right. They don’t want to dance with strangers then?
Ian - No.
Georgia - Just like most of us.
Ian - And that’s probably the difference between them and us that we can dance with strangers. There’s some very interesting ethnographic evidence; for instance when the first fleet landed in Botany Bay in Australia in 1788 - sorry, invaded Australia - more or less the first thing that happened was that some of the sailors danced with some of the indigenous peoples.
Georgia - You mentioned we think that dance evolved because of a social thing, is there anything else it might be good for and has anyone done these studies into this?
Ian - We did a study about three or four years ago where we looked at people dancing together and the effect that that had on memory. We used silent disco technology to enable us to have two groups of people dancing in the same space but to different pieces of music. Silent disco technology, for those who don’t know - wireless headphones with a base station. The base station can broadcast the music, and you’ve usually got two or three or maybe half a dozen different channels on the base station. We used two different channels, two different pieces of music, so half the people were dancing to one piece and half were dancing to a different piece at a different tempo, different speed.
Georgia - And what effect did that have on people's memory did you say?
Ian - Well, what we did is control the ways in which they could interact with each other. So everyone spent as much time in proximity to people dancing at the same tempo as dancing at the different tempo. People were wearing different coloured sashes and half of them were wearing badges. What we found was that people remembered the colour of the sashes that people dancing to the same tempo were wearing, and remembered whether or not people dancing to the same tempo were wearing badges. But didn’t remember nearly so well when they were dancing to a different tempo.
Georgia - So dancing might actually help us remember things about the people we're dancing with? Why would that be a good thing evolutionary speaking?
Ian - Well, what you are remembering are incidental features; features that are not focally attended to. It’s pretty good just to check up, “can I cope with this person? Can I engage with this person? Will I be able to communicate with this person?”. And if you add another layer to it then, of course, the whole sex thing comes into it. But we’re talking about a level here way below that which is just general sociality.
Georgia - I see. So you’re having a nice dance with someone, maybe had a bit to drink and you dance really well with them. But then, who were they? And then you remember what colour sash they had on.
Ian - That could be one aspect. Some other research has shown we’re more likely to like people we have been in time with than people we’ve been out of time with.
Georgia - I guess that’s similar to how they make people do marching together for armies and things. It’s very important, isn’t it?
Ian - Yeah. It is a process of bonding. At that level, to distinguish between music and dance becomes a bit silly because in most world cultures they are the same thing.
Georgia - I was going to ask about that because music is another thing that’s very linked with dancing, and you say that they’re sort of the same in many cultures?
Ian - Yeah, absolutely. And in many respects the same in this culture. In Nigeria, for instance, in Igbo what we might think of as music is “nkwa”, which is music, singing, dancing and having a good time.
Georgia - Right. So they’re all one word?
Ian - Yeah.
Georgia - That’s a lovely word.
Ian - It is. And it’s a much more sensible word than music, which kind of partitions out an area of human experience, or dance which again partitions our another area, which are closely linked.
Georgia - Do we know what happens in a brain when a great tune comes on, and your foot starts tapping away and you just want to have a boogy? What’s going on inside our minds to cause this reaction?
Ian - One of the interesting things that happens when we hear music is that the bit of the brain that’s involved for planning for action, the supplementary motor area, there’s activation. The supplementary motor area; there’s activation. A meter analysis of all the studies that have looked at people just listening to music in a scanner showed that one area that was consistently activated was the supplementary motor area. So you could say that a response to listening to music is to prepare to move.