The Expectation Effect by David Robson

Review by Terence Jagger

We are all aware of placebos and their effects – the idea that a totally inactive substance can have a similar effect to, for example, a potent drug, something which persists even if the recipient knows it is a placebo. This book deals with placebos and with the opposite effect, nocebo – where negative effects can arise from expectations about the effects of – for example, vaccinations – which are actually unfounded and unreal. This comes down to the heart of the book, the real effects on all of us of our prior expectations, however raised. Robson is at pains to make it clear he is talking about specific beliefs, either positive or negative, and scientifically observed and explained phenomena, not the pseudo-science of thinking yourself rich or happy.

In one Harvard study, hotel cleaners’ weight and blood pressure improved, not because they improved their lifestyles, but because they were told they were doing enough exercise for a healthy lifestyle. Drugs’ unpleasant side effects are often the result of the patient knowing about the possibility and expecting them, beer tastes better or worse when we change the name, and the same equipment works better or worse for us depending on what we expect in advance; and expectations can make us see and hear things which are objectively not there. In extreme cases – the non-existent drones over Gatwick in 2019, or a migraine patient called Sara – they can lead to multiple, sustained illusions, or tragic effects, as when Sara became completely blind for no organic reason at all (with appropriate therapy, she regained her sight fully). But these are dramatic effects caused by our brains’ expectations, and to a very real extent, we do not see things as they are, we see them as we are (Anais Nin); seeing isn’t believing, believing is seeing (Robson’s summary).

Placebos have been known in medicine for centuries, but they have mostly been disregarded as serious medicine – indeed, there was a view that if a placebo worked, the patient didn’t really have an illness, so they must be malingering or delusional. But Henry Beecher found marked placebo effects from using saline solution when he had run out of anaesthetic in Second World War battlefield surgery – and no-one could argue that these extreme wounds and broken bones were not real. So a whole new interest developed, although serious concerns remained about doctors using placebos, as it seemed to involve them in dishonesty to the patient.  But evidence is increasingly strong that the placebo works even when the patient knows about it, and that the benefits persist, sometimes over years – as in Claudia Carvalho’s seminal study into acute back pain.

But in addition to the placebo, there is also a nocebo effect, where expectations create bad and painful outcomes, notably in side effects to taking medicine, where warning people about rare side effects creates many severe and painful outcomes, even when patients are in fact not taking the medicine in question but an inert substitute. A misdiagnosis of a serious illness can apparently cause death, when the real diagnosis would have been much more benign. Patient belief about the seriousness of their brain tumours, for example, is the best predictor of their outcomes and recovery success. This poses some real problems – it might be really helpful to not tell people about the possible dangers of their medicine, but it seems immoral; but two things can help – a new protocol in which the patient agrees they do not want full information on rare outcomes; and improving the language they are warned in – so 10% of patients taking this medicine get severe headaches creates many, many more headache sufferers than 90% of patients suffer no headaches.

Robson describes how the expectation effect can lead to people catching entirely imaginary illnesses, citing one Portuguese incident where thousands of children across the country caught a mystery (and actually non-existent) illness, initially from a soap opera, and then from each other!  But there are many other examples, including many (but of course not all) of the surprisingly large number of intolerances to substances like gluten – which in many cases persist when all gluten is absent, which is not the case for real intolerance, of course. And Robson himself describes suffering from shortness of breath and other symptoms from wearing a mask during covid – and absurdly caused by hearing people talk about such reactions – which he cured by doing some proper research and finding, among other things, a video of a cardiologist doing his regular workout in a surgical mask – thus reversing his (Robson’s) expectations.

When dealing with expectation effects, either placebo or nocebo, the area of medicines is the obvious one, but there are fascinating chapters on a range of non-medical issues, although many of them do affect health. For example, a cyclist drug cheat given a placebo injection by a worried team doctor massively outperforms his previous best. And it is a commonplace that emergency can bring forth massive and unexpected strength – people lifting crashed cars off their children for example. The reason for this is apparently that the brain is really quite conservative about setting expectations in this area, perhaps to avoid injury – and that when an athlete has “given their all” and genuinely feels utterly exhausted, there is actually both muscular and aerobic capacity remaining – which can be utilised in escaping a lion or rescuing one’s child. More extraordinary still, to my mind, is the fact that intellectual exercise can reduce one’s subsequent physical performance, so don’t do the Times crossword before that charity marathon! And of course, a lot of us have bad experiences from compulsory school sport, and believe we are not fit and can’t excise – but doing basic physiology or fitness tests then telling people they performed above average (true or not) works wonders and they immediately improve.

Similar effects are seen with food, but with a crucial twist. If you are told food is going to make you feel full for longer, it really does, and this is demonstrated in both your sense impressions, and in the biochemical reactions in your digestive system – the chemicals which make you feel hungry or full are directly affected. And you even absorb more nutrients from the same food if it looks attractive and sustaining – so eat a proper meal, laid out nicely, not a slurry or baby food form! And thinking about your food, and how nice it is, forms memories which keep you full – so when a snack if offered, remembering your last meal, in detail if possible, makes you less likely to accept it. And diet foods are often the worse for you in this sense – words like ‘lite’, ‘healthy’, guilt free and so on can actually signal to your brain that there’s not much in these foods, so you feel hungry afterwards (even if they are actually as, or more, filling than the so called unhealthy or indulgent foods). Feeling good about food is important, and thinking it will make you feel good, nourish you and sustain you are really important parts of the process. So avoiding sugary drinks is healthy, but this is true because the brain tends to assume liquids don’t have a lot of calories, and eating with attention is good because it forms memories which keep you full when working or watching TV might make you forget.

Very similar findings are presented in the following chapters, on managing stress, on maintaining energy and willpower for mental effort and concentration, and on intelligence and academic performance. In every case, there is clear, experimentally reliable evidence that expectations shape outcomes – whether these are expectations deliberately managed, or even communicated accidentally and unknowingly, like the maths teachers who only ask boys the questions and depress girls’ achievements. Robson quotes Eliza Doolittle in G B Shaw’s play Pygmalion, because it is so apposite that it is quoted in one of the main studies of expectation in schools: 

You see, really and truly, apart from the things anyone can pick up (the dressing and the proper way of speaking, and so on), the difference between a lady and a flower girl is not how she behaves, but how she’s treated. I shall always be a flower girl to Professor Higgins, because he always treats me as a flower girl, and always will; but I know I can be a lady to you, because you always treat me as a lady, and always will.

In a final chapter, Robson looks at ageing, and how a positive view of getting older has a marked effect both on life expectancy and on physical and mental activity. He quotes the example of people who salsa dance in their 80s, marathon runners who took up the sport only on retirement. Key here is the view individuals have of older people, and often – and unfortunately – these are their own views, formed when they were much younger.  So they may associate age with a physical slowing down, mental fading, and increasing pain and discomfort. It might take a real effort to see age as an opportunity to do what you really want, to learn a new skill, make new friends and explore new places. But some people do all these things with enormous success – although naturally genetics, environment and even chance can make a difference too. As with other issues in the book, it is not a case of positive thinking miraculously overriding other negative factors like being ill-prepared or poor education, but of consideration of whether a negative view has been irrationally arrived at, and a more balanced (hopefully more positive) understanding achieved, which in turn influences the brain’s forecasting – leading to more positive outcomes. And of course behavioural issues come into play too – if you think you cannot exercise, you don’t, and then you will become unfit, and thus less able to exercise.  

The brain evolved to make predictions, drawing on our own previous experiences, our observations of others and of our cultural norms – a process that underlies our very perception of reality, and prepares the mind and body for whatever it has to face.  And we now know the ways we can reappraise those expectations to create our own self-fulfilling prophecies …  Ideally practising these skills should become a habit – we probe and question the framing to see if we are accidentally forming a negative self-fulfilling prophecy with no rational basis. 

And if this is not immediately or always successful, Robson suggests remembering that your mind is not fixed, but a work in progress, this may take time; you may need to take an outside view – what would a friend say about your situation, for example.

All in all, I found this a lovely and fascinating, even inspiring, book. It is scientifically based and clearly explained, aimed at the intelligent layman without technicalities or jargon, but with plenty of evidence and examples.  I recognised myself in many of his comments – a mixture of positivity about certain types of outcomes, and negativity about others. It’s a bracing and interesting challenge to see if, by examining the basis of our beliefs through evidence and clear thinking, we can actually change personal outcomes for the better in a whole host of ways.  

David Robson, The Expectation Effect: How Your Mindset Can Transform Your Life  (Canongate, 2022). ISBN 978-1838853266, 231pp, hardback.

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