Name: how expectations shape placebo results
Uploaded: 2020-02-12T11:07:40.000Z
Duration: 1 min 54 s
Channel: JoVE

K12 Standards

Virginia  Standards of Learning

HIgh School

Biology

BIO.1

BIO.1.b

The Placebo Effect

When exposed to a new treatment, people may react positively due to psychological factors, rather than the actual medicine being administered.

For example, a researcher conducting an experimental study on an antidepressant&rsquo;s efficacy may begin by telling participants they&rsquo;ll receive a pill anticipated to decrease symptoms like insomnia and anxiety.

However, during the investigation, only half of the individuals receive and take the drug. The remainder are given a placebo&mdash;such as an inert sugar pill&mdash;that lacks medicine and isn&rsquo;t expected to alter body chemistry.

Interestingly, during assessment, both groups note better sleep and less anxiety. The fact that individuals administered the sugar pill also report improvement is referred to as the placebo effect&mdash;a response that occurs when someone&rsquo;s pre-existing beliefs influence the experience in a given situation.

Multiple factors influence this phenomenon, among them an individual&rsquo;s surroundings and interactions. For instance, a participant might notice several promising papers on depression in the scientist&rsquo;s office.

This environment, paired with the researcher&rsquo;s sympathy and confidence that the study will help the subject&rsquo;s depression

the placebo effect

The placebo effect occurs when people&#39;s expectations or beliefs influence or determine their experience in a given situation. In other words, simply expecting something to happen can actually make it happen.

The placebo effect is commonly described in terms of testing the effectiveness of a new medication. Imagine that you work in a pharmaceutical company, and you think you have a new drug that is effective in treating depression. To demonstrate that your medication is effective, you run an experiment with two groups: The experimental group receives the medication, and the control group does not. But you don&rsquo;t want participants to know whether they received the drug or not.

Why is that? Imagine that you are a participant in this study, and you have just taken a pill that you think will improve your mood. Because you expect the pill to have an effect, you might feel better simply because you took the pill and not because of any drug actually contained in the pill&mdash;this is the placebo effect.

To make sure that any effects on mood are due to the drug and not due to expectations, the control group receives a placebo (in this case a sugar pill). Now everyone gets a pill, and once again neither the researcher nor the experimental participants know who got the drug and who got the sugar pill. Any differences in mood between the experimental and control groups can now be attributed to the drug itself rather than to experimenter bias or participant expectations.

This text is adapted from <a href="https://cnx.org/contents/Sr8Ev5Og@10.24:mfArybye@16/2-3-Analyzing-Findings" target="_blank">OpenStax, Psychology. OpenStax CNX.</a>

The placebo effect occurs when people&#39;s expectations or beliefs influence or determine their experience in a given situation. In other words, simply ...

Education

JoVE Core

Social Psychology

Foundations of Social Psychology

Research Methods

KEY TERMS AND CONCEPTS

how expectations shape placebo results

The placebo effect shows how expectations and beliefs can shape what people experience. In some situations, simply expecting something to happen can make it feel real. This effect is often discussed when scientists test a new medicine.

A common example is a study on depression treatment. A pharmaceutical company may compare two groups. The experimental group receives the medication, and the control group does not. To keep participants from knowing which treatment they got, researchers may give the control group a placebo, such as a sugar pill.

This setup helps separate the drug’s real effect from the effect of expectation. If a participant thinks a pill will improve mood, they may feel better even if the pill contains no drug. That change comes from the placebo effect, not from the medicine itself.

Researchers also use this method to reduce experimenter bias and participant expectations. When neither the researcher nor the participants know who received the drug or the sugar pill, the comparison is more reliable. Any mood differences between the groups can then be linked to the drug rather than to beliefs about the treatment.

How Expectations Shape Placebo Results

the scientific method

Research Questions and Falsifiable Hypotheses

Research questions and falsifiable hypotheses help scientists separate facts from opinions. Facts are observable realities. Opinions are personal judgments, conclusions, or attitudes that may or may not be accurate. In science, facts are established with evidence from empirical research, which means research based on observation and experience. Scientific knowledge grows through the scientific method, a process that connects ideas with real-world evidence. Researchers test theories and...

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factorial design

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The placebo effect shows how expectations and beliefs can shape what people experience. In some situations, simply expecting something to happen can make it feel real. This effect is often discussed when scientists test a new medicine. A common example is a study on depression treatment. A pharmaceutical company may compare two groups. The experimental group receives the medication, and the control group does not. To keep participants from knowing which treatment they got, researchers may give...

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ethics in research

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correlations

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variation: normal distribution, range, and standard deviation

variation-normal-distribution-range-and-standard-deviation

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statistical significance

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key terms and concepts

See how the placebo effect can change study results, why sugar pills are used, and how researchers test whether a medicine really works.

How Expectations Shape Placebo Results | JoVE K12

JoVE Core Social Psychology offers a comprehensive learning experience on the principles of social behavior through concise, animated video lessons. The series explores key topics such as self-concept, social cognition, group dynamics, stereotypes, and relationships. It provides a structured foundation for understanding human behavior in social situations. Students gain insights into how individuals think, feel, and behave in social contexts while examining the psychological processes that influence interactions and judgments. By integrating theory with real-world applications, these lessons offer a clear and engaging approach to mastering essential concepts in social psychology.

social psychology

Chemistry

CH.1

CH.1.b

Texas Essential Knowledge and Skills

High School

CHEM.4

CHEM.4.B

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BIO.1.f

How Expectations Shape Placebo Results

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