This documentary (with the brilliant strapline ‘The film that half your brain doesn’t want you to see’) takes a look at the arguments articulated by Dr Iain McGilchrist in his groundbreaking and controversial book, The Master and His Emissary: The Divided Brain and the Making of the Western World. 

McGilchrist argues that our brains have two radically different ways of thinking: that of the left hemisphere, which breaks things down into their constituent parts and seeks to explain the world through logic and categorisation; and that of the right, which helps us see the bigger picture, make links and view things in their proper context. Both are essential, and the way we view the world has varied throughout history but, he argues, we have become dangerously dominated by reductive left hemisphere thought.

We get to see real-life examples of the brain patients described in the book, such as single-hemisphere stroke victims with fully-functioning eyes who are unable to see things down the affected side, or whose left and right hands are incapable of working towards the same objective. But like the book, this documentary does rather less to develop the argument that the role of these hemispheres has been instrumental in human history.

It draws attention to the three major leaps forward in Western civilisation: ancient Greece, Rome and the Renaissance, arguing that in each case a flourishing in human culture facilitated by a balance of left and right brained thought preceded a shift to left brained dominance which ultimately led to their downfall. And now, he argues, this is happening again.

It’s difficult to make a completely watertight case for such a grand theory since it’s only ever possible to cherry-pick examples. In this case the focus is on the art in those periods which initially focused on human emotion but later came to feature blank faces and status symbols. I lack the background knowledge and intellectual tools to seriously critique McGilchrist’s ideas (not that that stopped A. C. Grayling) but enough information is provided to give these ideas serious consideration.

Yet if you follow the line of argument to the end hoping for a strong call to action you will be disappointed, another flaw it shares with the book. The documentary argues McGilchrist can’t provide all the solutions, but when the person who has spent the most time thinking about this doesn’t even hint at what we can do about it, what hope is there for the rest of us?

While McGilchrist is unique in looking at neurological phenomena to explain problems in modern society, the issues he identifies, such as our increasing reliance on rules and categorisation, viewing the natural world as a resource to be controlled and consumed, and an inability to understand meaning in context, are not new. And while he may be correct about their root causes, could focusing on the inner workings of our brains rather than the bigger picture be the wrong approach to a solution, and a product of left brained thinking too? It seems much easier to argue for a society in which we remember to consider our place in the natural world than for every individual to re-learn how to think.

There’s also a risk in criticising our over-reliance on data and our inability to judge things based on intuition. While again this may well contain elements of truth, using data to form evidence-based policy seems enormously preferable to allowing decision makers to act on instinct. This is, after all, the decision making style of Donald Trump, and is used as an excuse to shun briefings and act on gut instinct. This isn’t to say McGilchrist isn’t right, but that we shouldn’t risk throwing the baby out with the bathwater in a complex society which relies on precision to function.

But while it may suffer from flaws, some of which are inevitable in such an ambitious work, it’s clear McGilchrist has at least two fully-functioning hemispheres. What results will engage your whole brain and is well worth a watch, especially if you don’t feel like reading the not entirely penetrable source material.

Watch The Divided Brain on Vimeo