In Part 1 of his most recent book, The Matter With Things. Our Brain, Our Delusions and the Unmaking of the World, Iain McGilchrist discusses The Hemispheres and the Means to Truth. Currently I am reading and discussing the nine chapters that make up this first part of the book with a group from Channel McGilchrist, who meet once a month to discuss one or two chapters at a time. To date we have met and discussed Chapters 2 and 3:
In Chapter 4 McGilchrist discusses Judgment as a means to truth and asks the question, what roles do the hemispheres play in reaching beliefs and making judgments?
In Chapter 4 McGilchrist notes the difference but also overlap between hallucinations which result from perceptual distortions associated with right hemisphere dysfunction, and delusions (distorted reality judgments) which also result from right hemisphere dysfunction. He writes (p.135)
‘Distinguishing delusions (distorted reality judgments) from hallucinations (distorted perceptions) is to some degree arbitrary, since misperceptions can give rise to misbeliefs, and misbeliefs give rise to misperceptions. Added to which, all perceptions involve a judgment undertaken before we are aware of it. We don’t see a shape, a texture, a bunch of colours, and only then deduce ‘a tree’. We see the tree whole and immediately, because somewhere way below consciousness we are discriminating what fits best in the context in which we find ourselves.’
Altered perceptions are treated separately from altered judgments in psychiatry, but it is artificial to separate them as they might affect each other. Altered perceptions result in things like hallucinations; altered judgments result in thinking bizarre things or delusions. The question is, how much can we trust the testimony of the left and right hemispheres? On its own the left hemisphere tends to delusion.
The thrust of this chapter is summed up on p.180, where McGilchrist writes that ‘Virtually all delusional syndromes are more commonly the result of right hemisphere than left hemisphere dysfunction; ….’ And ‘Overall, in general it is the judgments on reality made by the right hemisphere that are more reliable.’
In the preceding 45 pages, McGilchrist presents an extensive synthesis of the research into hemispheric difference in pathologies of judgment (e.g., delusional misidentification, paranoia, Othello syndrome and more) and altered role of the body (e.g., Phantom limb, xenomelia and more). To be honest, I found this chapter tedious. Perhaps this is because after 10 years or so of reading and re-reading The Master and His Emissary, I don’t need further scientific research to convince me that we are living in a world dominated by the left hemisphere. I am more interested in what the implications are for how we live our lives.
Some of the ideas in this chapter that might implicitly inform how we live our lives relate to:
Pessimism, optimism and realism (p.150)
- the left hemisphere is .. unreliable in daily life: it has a tendency to jump to conclusions, to become entrenched, to be unwilling to see other points of view and, frankly, to make stuff up, if it needs to, in order to maintain its point of view. It has a desperate need for certainty. (p.154)
- Optimism is related to denial by the left hemisphere.
- Insight is very largely right hemisphere dependent. (p.150)
- Although relatively speaking the right hemisphere takes a more pessimistic view of the self, it is also more realistic about it. (p.150)
- … depression has repeatedly been shown to be associated with greater realism – provided the depression is not too severe. (p.150) Depressed patients make better judgments.
- The evidence is … that.… up to a point, being depressed gives you insight. (p.150)
- Insight into yourself and your own illness is dependent on the right hemisphere.
- The right hemisphere is important for reality testing.
False ‘memories’ and confabulation (p.155)
- … the left hemisphere just is not reliable about the self. And since, in a sense, the self is all we know directly, that’s got to be a handicap.’ (p.158)
Magical thinking (p.158)
- Magical thinking is associated with creativity. (p.158)
- … ‘magical ideation’ is by definition not in itself delusional, though it may be on a continuum with delusion. It simply suggests a greater willingness to consider connexions, some of which are no doubt non-existent, but some of which may simply not be recognised in the current Western standard model. (p.1610
- … to be ‘totally “unmagical” is very unhealthy’, and reduces one’s capacity to appreciate value and to take enjoyment in life. (p.162)
- Most people engage in magical thinking. There are certain truths that can only be understood through a myth. Deep truths can’t be encompassed in words.
Judgments formed on intuition (p.162)
- There are differences between men and women. There is more specialisation in each hemisphere in men, and more overlap between the hemispheres in women.
- In normal adults, sex differences in functional cerebral asymmetries have been reported in a wide range of areas, including decision-making …. but extending to areas such as language, working memory, spatial orientation, spatial attention, face perception, verbal and musical creativity tasks, emotional ‘processing’ and appreciation of beauty. Except in the case of language, males have generally been found in every one of these areas to be more reliant on the right hemisphere than females. (p.163)
The role of reasoning in forming judgments (p.167)
- both hemispheres contribute to reasoning. (p.167)
- the old dichotomy – left hemisphere rational, right hemisphere emotional – is profoundly mistaken, on both counts; not to mention the fact that reason and emotion are never entirely separable. (p.167)
- the tendency of the left hemisphere is to treat things as more certain than they are. (p.169)
- Induction is associated with the left hemisphere. Induction is based on an assumption of the normal and expectable (p.169). The left hemisphere tends to reach hasty conclusions on the basis of what seems likely. (p.170)
- The left hemisphere is more likely to act on its theory as though it represented reality. (p.179)
- Deduction … is seeing something is implied by what one knows, and is latent or implicit in it …
- … the right hemisphere is our bullshit detector. (p.172)
- … unlike the left hemisphere, the right hemisphere can operate with several types of uncertainties: inexactness, incompleteness, probabilities, fuzziness, observer error and so on. (p.174)
So, as McGilchrist writes in the summary to this chapter (p.180)
‘Both hemispheres play a part in reasoning, and when the situation is relatively simple, completely specified and the outcome in accord with expectation, the left hemisphere plays the key role; when any of these conditions does not apply, the right hemisphere is more reliable and veridical.’
As on the previous zoom calls, although the discussion was interesting and enjoyable, I did not feel any the wiser at the end of it. More questions were raised than answered, such as:
- In a non-clinical setting, is it possible to be able to identify predominantly left hemisphere individuals? If so, could two of the identifying traits be blanket cynicism and fragmentation?
- Is it possible that hemisphere specialization or preference could lead to the evolution of two distinct human species? Homo Machine/Bureaucrat v Homo??
- How do we use this work to understand early childhood development?
- What are McGilchrist’s genuinely helpful contributions to neuroscience or philosophy? How do we best judge the value of his work?
- What is belief? How does this differ from world view? Where does emotion or pre/unconscious fit into belief? Is personal investigation the best way to find truth?
Thanks to Laura Thomas for collating these questions.
The next meeting of this reading group will be on Friday 8th July at 4.00 pm UK time, to discuss Chapters 5 (Apprehension) and 6 (Emotional and Social Intelligence) of The Matter With Things.
McGilchrist, I. (2021). The Matter With Things. Our Brains, Our Delusions, and the Unmaking of the World. Perspectiva Press.
McGilchrist, I. (2009). The Master and his Emissary. The Divided Brain and the Making of the Western World. Yale University Press.