Divided Brain, Divided World

You’ve probably heard of the left-brain / right-brain divide, and you might also feel that it’s a bit unfashionable now – a simplistic theory which has been superseded as our understanding of neuroscience grows.

That’s how we always saw it too. But then we started looking into more recent research on brain lateralisation (i.e. the way the different brain hemispheres work) and we found a very different story.

Short version: what you think about the left- and right-brain is almost certainly wrong. The divide between them does matter – in fact it may explain a lot, not just about modern marketing, but about modern life.

Central to our new understanding of the right and left brain is a psychiatrist and neuroscientist called Iain McGilchrist. He’s probably the world’s leading expert on brain lateralisation. His recently reissued book, The Master And His Emissary, collates the last two decades of work in the field to explain what the relationship between the left and right brains really is.

The key misconception is this. Popular science portrayed the left and right brain as doing different things – art and science, creativity and logic, and so on. Neuroscience has debunked this – both hemispheres are active in most mental operations. The left and right brain don’t do different things. Instead, they do things differently.

According to McGilchrist, our left and right brain attend the world in different ways – relating to and responding to different aspects of it, and inclining people to express themselves in distinct ways.

The left brain has narrower focus and is more goal-orientated. Its tendency is to isolate parts from the whole and to see them in the abstract. It favours consistency and repeatability, likes to categorise, classify and to predict. It sees cause and effect, and seeks to manipulate the world through tools, the most important of these being language. It likes things to be explicit and cannot deal with contradiction.

This makes it both very literal and, being also the half of the brain that processes anger, dogmatic. It wilfully ignores anything outside its model of the world, so it lives in a self-referential hall of mirrors, ensuring an optimistic outlook. It controls language but has little gift for music, with a limited appreciation for anything much beyond rhythm. It has a poor perception of depth and little appreciation of its place in time, and struggles alone to see or recognise anything in the left visual plane.

The right brain on the other hand, sees the whole rather than the parts. Its attention is broad. It is rooted in bodily experience and empathy. It is comfortable with the implicit, and is able to understand feelings in the faces and expressions of others. Its structure enables it to see the relationships between things. If language resides in the left hemisphere, music is the natural mode of the right, because its ability to see connections, perceive depth and appreciate the passing of time also enables it to enjoy melody, timbre and harmony.

This way of attending to the world means it’s also more given to melancholy and nostalgia. Its broad focus means that it attends to anything novel. It’s exploratory and has the flexibility to cope with contradiction. Its ability to hold two competing thoughts at once enables it to understand metaphor, humour and irony, and makes it naturally more open to both cynicism and spirituality.

In literary terms, the left brain taken to an extreme is Dickens’ Gradgrind – the productivity-minded educational reformer determined that children should learn only facts. The right brain might be Proust’s Narrator – melancholy and nostalgic, alive to every nuance of human interaction but constantly diverted by his senses and prone to drift.

Most of us might have stronger inclinations in one or other direction but we navigate the world with our left-and-right brains working in tandem. The right side of the brain understands the world, the left acts upon it.

McGilchrist’s book offers a provocative hypothesis. He asserts that humanity flourishes when there is hemispheric balance in the way a given population attends to the world. When the left brain dominates, he says, you see greater abstraction and a literal flattening of culture. Ways of thinking are imitated and so re-enforced across a population, and the self-referential nature of the left-brain makes it difficult for it to see any other point of view, so groupthink and dogma set in. Left-brain attention has undoubtedly moved business and scientific enquiry forward, but McGilchrist asserts, for all its brilliance, an increasingly dominant left-brain mode of operating in the West is also causing many of today’s ills, from environmental change to mental health problems, and its hallmarks can be seen in everyday culture around us.

One example which makes these ideas easy to grasp is art, which McGilchrist considers in detail. Art is not the sole domain of the right brain: the left and right brain both perceive art and are both involved in the making of art. He sees the Renaissance, for instance, when artists rapidly rediscovered and adopted perspective, as a period where left-brain dominance gave way to hemispheric balance and art literally became less flat.

This is the Fair At Lendit Near St-Denis, from a medieval manuscript. McGilchrist sees this style of art as left-brain dominated. Notice the lack of depth perspective and preference for hierarchy communicated via size – like a 15th century org chart!