A True Human Invariant

Every human culture and society has music. It seems to be hard-wired into the human brain, our genetic structure, and the human voicebox is one of the most remarkably versatile organs in nature. But why should this be so? What survival characteristics are enhanced by music, that it should be so deeply embedded? After all, it doesn’t seem to be helpful in putting food on the table (but see below), or building a shelter, or anything else you can directly point to and say “This helps us survive as a species”. Except perhaps courtship. Music can be used to communicate to others your availability and desirability as a mate, and is clearly used in this fashion in some other species. In fact, a large proportion of the songs that are produced deal directly with our mating desires.

But most people are not great singers or instrumentalists – and listening to some of the contestants on American Idol, I would think that some of the ‘singing’ done there would actively turn off any potential mate. Very few can write a song. If only a very small part of the population can produce, in one fashion or another, something pleasing enough to actively attract others, then it’s hard to see how music can strongly effect mating choices and thereby enhance survivability.

Perhaps we need to look at some of the other effects music has.

Now one characteristic of music is rhythm, and the typical frequency of rhythms present in almost all music is close to the normal human heart rate. Some studies have shown that the heart rate adjusts itself to be close to whatever the ‘beat’ of the music is. What most people consider to be ‘relaxing’ music has comparatively slow rhythms, similar to the heart rate when ‘at rest’. The converse is also true – music with accelerated rhythms produces a quickening in the heart rate. Right alongside the heart rate effect is the apparent effect on brain rhythms, which seems to follow a similar pattern (and leading to some claims that playing Mozart will increase your child’s intelligence).

One strong item which derives from this is the ‘synchronizing’ effect between the music and the actions of the person listening to it. People are not normally very good at accurately timing their actions – typical is perhaps getting within 10 – 20 milliseconds of when they wanted to do something – but when trying to, say, match the timing of words in a song, most people can get a lot more accurate, near 1 – 2 milliseconds. This might be a good ability to have! Especially when looked at in terms of a group of people. Imagine a group of hunters who need to coordinate their attack on a large animal. A song with a strong beat will allow these hunters to precisely time their actions, and be more successful in bringing down their prey. This accuracy in timing is apparently due to the ability of the brain to pre-process all the needed setup for the action before it actually needs to occur, based on the repetitive nature of the beat. So here is one benefit that can actually help us survive.

But music has a whole host of other effects on the human body, from skin galvanic levels to production of various hormones and other chemical facilitators. What survival attributes these effects have is not very clear. But apparently, over our long evolutionary course, these responses to rhythmically produced tones had some benefit to the individual’s ability to survive and propagate the trait.

But regardless of how it came to be, one of the strongest attributes of listening to music is pure pleasure, in some ways akin to a drug ‘high’ (possibly this effect is mediated by the same chemical ‘triggers’ in the brain). Music is addictive and (normally, when not played at 120 db) harmless, and I for one am very happy that today’s technology allows me to get my ‘fix’ almost anytime and anywhere I want.