Takeaways: The Expectation Effect

I read somewhere that writing summaries is more important than reading books. So I decided to take that author’s advice, and also his template.

I recently finished reading The Expectation Effect: How Your Mindset Can Change Your World by David Robson. In summary, I thought it was great!

In 1-2 sentences, what is the book about as a whole?

Humans are profoundly influenced by our expectations, which not only color our perception of the world but also causally influence physiological processes. The well-known placebo and nocebo effects are one version of the broader expectation effect.

What are the 3-4 central questions it tries to answer?

  1. To what extent do our expectations influence our perceptions and outcomes?
  2. Why should we believe that this effect is causal?
  3. How can we harness the power of the expectation effect to improve our lives?

Summarize the answers in one paragraph each.

1) To what extent do our expectations influence our perceptions and outcomes?

The human brain is a prediction machine. It does not process all of the inputs from our senses to understand reality, but rather it instead makes predictions about reality based on a sample of inputs and proceeds accordingly. When faced with a mismatch between prediction and inputs, the brain will sometimes sound an alarm to resolve the conflict, but often enough it will simply discard the conflicting inputs. The brain engages in this smoothing over of reality so regularly that we are rarely surprised as we go about our day. This aligns well with plenty of anecdotes that we’ve heard about human biases. For example, when the sommeliers fall for the ‘re-labeled cheap wine’ trick, or when they fail to distinguish white wine with food coloring from red wine, their taste buds are being influenced by their expectations. The same logic applies to the idea that we ‘first eat with our eyes’.

2) Why should we believe that this effect is causal?

The author makes use of evidence from the vast volume of placebo-controlled studies in the scientific and medical literature. We know from the literature that the placebo effect is responsible for real physiological outcomes, often with effects comparable to pharmaceutical and surgical interventions. The more dramatic the placebo the more powerful the effect. Placebo pills works, placebo injections work even better, and sham surgeries work best of all. There are examples of placebo drugs providing pain relief almost as effective as opioids and placebo surgeries working just as well as real ones. There are also examples of cultural beliefs leading to population-level health variances. There are also non-medical examples of this causal effect. One is the famous study (also referenced in Carol Dwek’s Mindset) about housekeepers’ improved metabolic markers when they were told that their work counts as exercise.

3) How can we harness the power of the expectation effect to improve our lives?

The author suggests that knowing about the expectation effect and believing in its power can create virtuous cycles that improve our lives. Of course this does not mean that any old expectation manifests in reality — believing you don’t have cancer when you really do won’t make it go away, for example. However, there is plenty of evidence in support of the power of positive thinking and beliefs. Those who expect to be able to retain their youth and vitality as they age are more likely to do so. Those who expect exercise to be energizing rather than draining are more likely to get their way. Those who expect stress to be bad for them are more likely to suffer its ill effects. So by working earnestly to believe that good outcomes can happen to us and framing challenges and struggles in positive ways, we can tip the scales in our favor.

What are the most important things you have learned personally?

When I first heard about studies that showed the placebo effect worked even when subjects knew they were taking a placebo, it stuck with me. I recounted this oddity to plenty of folks over the years, and it was always with some awe. This book gave me a broader base from which to appreciate this fact of nature. This base fits with my past learnings from Mindset about the power of the so-called growth mindset. It incorporates my understanding that positive thinking leads to more positive outcomes. And that there’s a 2-way relationship between our mind and our bodies. Smiling can make us happy. Posture can impact our mood. Breathing can impact the state of our nervous system. I’ll be working to set my own expectations to my advantage, and by doing so I believe I will influence reality to my benefit.


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