Great Expectations Part 1 - Placebo, Nocebo, and Expectancy Effects

healthiermore productivewisersmarter

Jan 9

Written By Adam Fisher

Takeaway Points:

Expectancy effects are positive or negative physiological effects which occur as a result of the expectations that we’ve established for a particular course of action, training routine, method of treatment, pill, etc.
Placebo (positive) and nocebo (negative) effects are well documented, and vary in strength according to how strongly we believe a positive or negative effect will occur.
Scientific studies have to be carefully designed to avoid these expectancy effects, which can influence results.

An important concept when discussing the effect of any exercise or diet plan, is the effect that expectations can have on performance.

The human mind has extraordinary ability to adapt in response to its circumstances, and it tends to be biased in well-known and predictable ways, which I’ve written about previously on this blog.

Collectively, a variety of effects can arise from the result of different expectations - in short, the expectations you have of a given course of action, can have a very powerful effect on the outcome and effectiveness of that course of action. Most relevant to us is the effect that these expectations can have on the results of a fitness or diet intervention. So, I have started this two part post in order to explore how these expectations can impact our results.

Placebo Effect

The most commonly known effect of expectation is known as the placebo effect - the tendency to expect a good outcome creates a positive physiological effect which helps to achieve that outcome. This is most pronounced in medicine - if we expect that a pill will help us recover from an illness, then taking the pill will cause us to behave as if we are certain that we will improve, and as a result our symptoms improve - even when it turns out that the pill was a fake.

Placebo effect is commonly misunderstood to mean that our body contains secret powers of healing which are better than medicine - modern medicine is placebo-controlled, meaning that pills are tested up against placebo pills, and only those medicines which actually perform better than placebo alone are approved as potential treatments for a condition. In essence, when taking a medicinal pill, you’re getting the effects of placebo and whatever fundamental effects the pill actually has on fighting your condition, because it’s not a simple either/or. The placebo effect arises from taking a pill, any pill, because you believe that taking a pill will improve your condition. It just helps if, you know, that pill also works on its own.

Placebo effects can vary in strength and power depending on how believable the treatment is. If I receive a pill from a doctor in an office, who looks like a proper doctor, wears a medical coat, has a receptionist in the lobby and so on - I’m a lot more likely to get a powerful placebo effect because I believe in the narrative. I trust that this doctor is qualified and is giving me a sound treatment, because he looks the part. This can lead to some interesting effects - for example, in which placebo is enhanced by going to a fake doctor who looks the part and sounds convincing, but gives us a placebo pill (or is not actually a qualified doctor).

Conversely, a placebo effect is not likely to be strong if the story isn’t believable. If I’m ill and my buddy who has no medical training insists that I take a mystery pill to cure all my ailments, then I’m obviously a lot less likely to believe him. The narrative doesn’t fit, so the placebo is likely to be weak or non-existent. I already mistrust the effect.

Placebo can also vary in strength with how invested you are in believing that it’s likely to work. If I have a life-threatening condition, I’m more likely to want to believe that a pill will save my life because I have a lot more riding on it. Likewise, if I’m a serious investor in drug research and development, I’m more likely to experience a powerful effect when taking a pill that I’ve invested in, because I have not just my own health, but also my money riding on this pill’s success.

Placebo can also vary in strength with how invested you are in the person giving you the placebo. In the example I gave above, a doctor is a lot more believable than my medically untrained friend, because my doctor clearly has a lot more training in this field than my buddy. But if I valued my buddy’s opinion more highly than the doctor’s for some reason, I’d likely get a bigger effect.

This helps to explain the seemingly miraculous abilities of many cult leaders, gurus, and so on - often, people’s belief in the power of these figures is precisely what gives them power, by invoking the seemingly miraculous powers of placebo. The expectation is reinforced by the fact that other people also believe in the powers of the guru, especially if you value those people as friends.

Likewise, alternative medicine functions on a similar level - while most alternative medicine treatments are exactly those which tend to perform worse in carefully controlled studies, they still have some ability to effect improvement simply because people believe in, and trust, the power of the alternative medicine practitioner, especially if they have a very strong trusting relationship with that practitioner and want to believe in their treatments. The very narrative of being “against the establishment” or “using treatments your doctor doesn’t want you to know about” helps to establish the alternative practitioner as an alternate authority, and in a very real way gives power to their treatments.

These treatments may not harmful, or may not even be entirely useless - but their primary power to heal often arises from placebo and from the relationship between the practitioner and the patient. If someone has had particularly negative experiences with the mainstream medical establishment, for example, they may seek out alternative practitioners, place more trust in them, and even potentially get better results from inferior treatments, as a result of the power of placebo.

Nocebo Effect

Less commonly known, though equally important, is called the nocebo effect - the negative version of the placebo effect.

The nocebo effect can occur when a strong negative expectation is established, rather than a positive one. For example, one could imagine being told that a placebo pill is likely to worsen your recovery from a condition - obviously, you won’t want to take that pill, and if you do, you’d expect to see your recovery slow down because you trust in the negative power of that pill. The same effect could be displayed if someone was to play up or emphasize the potential side effects of a particular pill or method of treatment.

Nocebo effect functions similarly to placebo effect, with the power of the effect being related to how believable the narrative is. The more the believed credibility of the person slinging the nocebo, the greater we expect its effect to be.

Often, we see nocebo and placebo effects go hand in hand - if an alternative medicine practitioner talks down a traditional medicine treatment as well as talking up their own treatment, and if the person really trusts them, then we might see the traditional treatment fare worse, and the alternative better, at the same time.

This combination of positive and negative expectations is often very intertwined, and it’s hard to separate them out. Positive expectations for one course of treatment often come with negative expectations for other treatments. If we have close friends, for example, we’re far more likely to like other people that they like, and hate other people that they hate, because those expectations are wrapped up in our preference for that one friend.

Subject-expectancy Effect and Observer-expectancy Effect

The subject-expectancy effect, is a kind of effect which occurs as a result of a research subject expecting a given result. If the subject knows, for example, that research is being done on a potential cure for cancer, they will therefore expect that whatever treatment they receive in the process of the study is likely to cure cancer - and thus, experience a positive placebo effect as a result.

Likewise, observer-expectancy effect is an effect in which the observer (the person running the study) in a research study expects a given effect.

Let’s take an example of a study in which 50% of the participants are given a placebo, and 50% are given a potential cure for cancer which is being studied. This study will solve the problem of controlling for the placebo effect, since we can compare the placebo group with the cure group to see which does better.

However, if the participants were aware of whether they would be taking the placebo or the actual cure, this would ruin the data since the placebo effect would also be ruined. If they know which pills are placebo and which are the actual cure, they will thus experience the subject-expectancy effect and expect the placebo to do nothing and the cure to actually work - thus ruining the placebo effect.

Likewise, if the person running the study was to know which pills are placebo and which are the actual cure, this would cause an observer-expectancy effect. Because the observer knows which pills are which, they would be likely to subconsciously behave in ways that are encouraging or discouraging to the subjects. For example, they might be displeased with having to give placebo pills to a cancer sufferer, and thus subconsciously betray that the placebo pills are unlikely to actually work with their mannerisms and body language, once again ruining the placebo effect.

This is what we refer to when studies are referred to as “double-blinded” - this means that both the research participants, and the researchers conducting the experiment, do not know at the time which pills are which. The placebo pills have to be designed to look and feel identical to the normal pills, the assignments are randomized, and no one is told which pills are which until after the research is completed. In this way, expectancy effects can be avoided, and we can correctly identify which treatments perform best without any chance of placebo/nocebo effects having a significant impact on the outcome.

**The Effect of Any Change Whatsoever**

Expectancy can have an interesting, counterintuitive effect on interventions in our normal routines - that virtually any change at all will cause a temporary burst of positive results, even if it’s overall a worse approach.

Let’s say that your office is used to using a certain kind of software to manage the office tasks. Everyone uses the software, it works well enough, and everyone seems productive. But at the back of your boss’ mind, is always that nagging suspicion that things could be better, everyone could be more productive, and so on - and that all that’s needed is some superior productivity method that they haven’t tried yet.

So your boss decides to try out a new kind of software, in the hopes that this will boost productivity. Everyone tries it out, productivity increases, and the change is labelled a success - or at least, that’s the way it looks.

Maybe in the long run, the reality is that the software is actually slightly less efficient. It’s harder to use, slightly more confusing, or takes slightly longer each day to use. However, because everyone expected this approach to work better, they all subconsciously worked a little bit harder, thus leading to the expected productivity boost. Since the productivity boost was significant enough to convince your boss that the change worked, the change becomes permanent, the new method is adopted, and everyone does it that way from now on.

Worse, this can lead to a vicious cycle - a new method is adopted, productivity temporarily improves, the new method is praised, everyone returns to normal productivity, a new method is again adopted, productivity again improves, and the cycle continues. This cycle leads to constant change, which appears to create improvement, but actually just wastes a lot of time.

The end result is that virtually any change at all to the way things are normally done, can often lead to short term expectancy boosts like this, simply because we want to believe that the new way of doing things will be superior to the old one. Then, over time, people will get over the novelty of the new routine, settle back into a comfortable way of doing things, and productivity will return to normal. The actual effects of the change (if there are any) can’t really be determined until later on, after these effects have worn off.

There are also plenty of situations where changes won’t lead to positive expectancy effects, because the people simply didn’t expect them to work. At a previous job, I had a boss who was constantly changing the routine for the way that papers were filed - the very definition of a change without causing a significant difference, because how the papers were filed was ultimately irrelevant to how the business was run. Naturally, every time he announced a change, everyone would roll their eyes and do it the new way - no one actually believed that these ever-more-elaborate ways of filing things would cause any change, and of course they didn’t. Productivity didn’t really improve as a result, simply because no one really cared.

We have a powerful tendency to implement these kinds of expectancy effects in changes to our own habits, however. Whenever we decide to make a change, we have some reason to do so - after all, we don’t want to think that our current habits are necessarily bad, so when something comes around that we’d prefer to do differently, we have a tendency to assume that the new way must be better - we’ve already decided to follow it, so there must be merit to it!

Naturally, this has a tendency to show itself in the “newer is better” mindset, which leads people to program hop, constantly trying new diet and exercise approaches without sticking to any one long enough to see the real results of it. Privileging new things over old ones, simply because they’re new, leads to lots of little placebo “bumps” in results, but never actually gets you anywhere in the long run because you never stick to anything long enough to master it.

End Of Part 1!

Ok, so I let my keyboard get away from me, and ended up writing quite a bit on the subject. This week’s post primarily goes over the kinds of expectancy effects and how they function - next week’s part 2 post will analyze the practical applications when it comes to our health and fitness.

About Adam Fisher

Adam is an experienced fitness coach and blogger who's been blogging and coaching since 2012, and lifting since 2006. He's written for numerous major health publications, including Personal Trainer Development Center, T-Nation, Bodybuilding.com, Fitocracy, and Juggernaut Training Systems.

During that time he has coached hundreds of individuals of all levels of fitness, including competitive powerlifters and older exercisers regaining the strength to walk up a flight of stairs. His own training revolves around bodybuilding and powerlifting, in which he’s competed.

Adam writes about fitness, health, science, philosophy, personal finance, self-improvement, productivity, the good life, and everything else that interests him. When he's not writing or lifting, he's usually hanging out with his cats or feeding his video game addiction.

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