Neuroscience isn’t better than psychology

Photo by Reigh LeBlanc - http://flic.kr/p/6SCgsW
Photo by Reigh LeBlanc – http://flic.kr/p/6SCgsW

I was inspired to write this post after reading Dr Christian Jarrett’s article over on Wired. It’s a really good piece. It doesn’t go far enough.

I’ve been growing more confused over the last few years about the increasing tendency in all areas of society, including some academic circles, to treat neuroscience as a kind of scientific alternative to psychology. This tendency now comes in many flavours.

Want to know why some people are altruistic and generous whilst others are not? It’s because of brains.

Want to explain why some people are outgoing and sociable whilst others prefer to read a good book in a quiet room? It’s all about brains.

What about comparing dogs and people? How are they similar and different? Compare their brains, of course!

I’m a monist. I believe that the universe is made of matter, and that means we are too. Our behaviour is regulated by the interaction of our physical bodies with our environment, and much of what’s interesting goes on in our brains. I’m not suggesting that our brains receive messages from our ineffable souls à la Descartes. I’m quite certain that one day neuroscientists have discovered so much about the human brain that they’ll be able to build an entirely synthetic one.

None of this detracts from the fact that neuroscience operates at a very different level of analysis from psychology. Let’s take an analogy.

In school I studied electronics and I learned all about AND gates and bistables, and the other various pieces from which modern computers are made. I also learned all about subatomic particles including the mass of the electron, particle spin, and how electricity and magnetism are in fact two sides of the same coin.

A little while later, I had a brief career as a website designer. I learned how to write a page using HTML, develop SQL databases, and to code in Java and JavaScript. Not once during this time did I refer back to my notes on particle physics. I simply did not need to know how electrons move through a solid conductor in order to construct a nice looking web page.

As a culture, we know everything there is to know about computers. We built them. We could not make the modern silicon microprocessor wereit not for our considerable understanding of quantum physics. We know that that is how it works. You know as you sit in front of your computer now that when you scroll down the page it causes patterns of electrons to dance about in circuits inside the box. But if you were teaching someone how to browse a website, the last thing you would do is start your description with, “clicking this button sends a brief pulse of current through the blue wire inside this cable to the USB plug, which then causes a series of…” No. It’s completely the wrong level of analysis. A 1000-page manual could be written explaining precisely the signal representing a mouse-click passes through a computer’s BIOS, how it’s interpreted by the operating system and how this information is passed to the GUI and the application that receives focus. Would you read a 1000-page manual entitled “The left mouse click: A guide”?

Such is the case in the relationship between neuroscience and psychology. Neuroscience is never going to replace psychology, not because it is inadequate in comparison, but because each operates at a different level of analysis and therefore has distinct useful applications.

If one is doing science for the sake of figuring out stuff about the world (a fine and noble ideal) then most bets are off. You can investigate what you like, so long as you stick to a few basic principles like empiricism and parsimony. If, on the other hand, you are an applied scientist, wanting to intervene, then you need to choose your variables carefully. Just as an engineer pays closer attention to the aspects of bridge design she can alter.

The popular conception seems to be that if we can find evidence of something in the brain then it really does happen. Let’s do an experiment.

Blurg means the same as ‘red’.

Got it?

Blurg means ‘red’.

Red means blurg.

I just rewired your brain. If we had sufficiently advanced neuroscientific techniques I could watch the patterns of synapses firing differently now that you’ve got that new piece of learning under your belt. So what?

Knowing that the brain is the place where learning takes place doesn’t make anything more real. Just as two brains being ‘wired’ differently doesn’t tell us anything about how they got that way. Perhaps they just have lived different lives. Or perhaps they were hard-wired differently because of their genetics. (Clue, it’s always an interplay of the two.)

It isn’t just psychology that is diminished by this constant wheeling out of neuroscience. Neuroscience itself is sullied. A good deal of incredible research is being done in fields as diverse as motor neuron disease, alzheimer’s, and blindness. Excellent studies are being performed examining which neurons do what in the brain. Superb fundamental science. But I doubt it will ever be the case that encouraging someone in the office to be nicer to his colleagues will involve reference to his ventral tegmental area. This isn’t because neuroscience will be an inadequate description of behaviour. The field is progessing in the most impressive way. Such explanations will just not a usable in daily life. There will be too much detail. “Yes, I can show you how to memorise a phone number. First, your auditory cortex…

It’s time for us to stop fetishising neuroscience. If we want to support each other in behaving in helpful, altruistic, and successful ways, it’s the behaviour we need to concentrate on, not the brains.