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What are Demand Characteristics, How do they Affect Participants?

Published by at August 29th, 2023 , Revised On October 5, 2023

The field of psychology is packed with nuances that can influence the outcome of an experiment or study. One such factor is demand characteristics. 

But what are the demand characteristics in psychology? And, more importantly, how do they impact participants? This article delves deep into demand characteristics psychology to highlight its importance in experimental setups.

What are Demand Characteristics?

At its core, psychology’s demand characteristics definition is about the subtle, and sometimes not so subtle, cues that participants pick up from a study or experiment setting. These cues can influence participants to behave in a certain way, which they believe the researcher expects or desires. In essence, they are an extraneous variable that can distort the genuine responses or behaviours of participants, thereby affecting the validity of the research.

For instance, if a participant believes that the study is about the positive effects of a certain kind of behaviour, they might engage in that behaviour more than they would naturally, just because they want to be seen in a positive light or wish to ‘help’ the study produce significant results. This skewed behaviour is an outcome of demand characteristics.

Sources of Demand Characteristics

Understanding the sources of demand characteristics is crucial for researchers who aim to ensure the integrity and validity of their findings.

Instructions and Debriefing

The most direct source of demand characteristics arises from the instructions given to participants. If these are leading or suggestive, participants may alter their behaviour to align with the perceived expectation. Similarly, the debriefing process at the end of the experiment can give away information that might cause participants to reconsider or change their responses during post-test questioning.

Experimenter Behaviour

Sometimes, the experimenter’s non-verbal cues, mannerisms, or tone can unintentionally convey expectations. For example, suppose an experimenter nods slightly or offers encouragement after a particular response. In that case, the participant may interpret this as the “correct” or “desired” behaviour, thus influencing their subsequent actions or answers.

Setting and Environmental Cues

The location of the experiment, the presence of certain objects, or the overall setup can provide indirect cues about what’s expected. For instance, a room filled with health-related posters might cue participants to respond more favourably to health-oriented questions, even if the study is seemingly unrelated.

Interactions with Other Participants

In group experiments or studies where participants interact with one another, the opinions and responses of earlier participants can influence those who come after. This social influence can serve as a strong demand characteristic, especially if participants need to conform to what seems like the group norm.

Knowledge about the Purpose

If participants know the general purpose of the study or its objectives, this can shape their responses. For example, in a study about the effects of caffeine, participants who know the objective might report feeling more alert after consuming a caffeinated drink, even if they were given a placebo.

Previous Experiences

Participants involved in similar experiments or research studies may have developed certain expectations about how they “should” behave. This prior experience can be a significant demand characteristic, especially if the participant tries to be a “good” or “helpful” subject.

Feedback Mechanisms

If participants receive feedback during the study, whether about their performance or otherwise, it can influence their subsequent behaviour. For instance, if they’re told they performed above average on a particular task, they might become overconfident and careless in the next tasks or more diligent in maintaining their performance.

Cultural and Societal Norms

Beyond the immediate research setting, broader cultural and societal norms can serve as demand characteristics. Participants often want to present themselves in a positive light, in line with societal values. Therefore, they might respond in ways they believe are socially acceptable or desirable.

Why do Demand Characteristics Matter?

Demand characteristics can influence participants’ behaviour, which can affect the study results. Here’s why demand characteristics matter:

Threat to Internal Validity

Suppose participants modify their behaviour based on what they perceive the experiment expects. In that case, the observed effects may not be due to the independent variable (what’s being manipulated) but to the participants’ perceptions of what’s expected. This makes it difficult to draw accurate conclusions about cause-and-effect relationships.

Genuine Responses vs. Desired Responses

If participants try to please the experimenter, or if they believe they understand the purpose of the study and aim to confirm it, their responses might not represent their true feelings, beliefs, or behaviours.


Awareness of one’s behaviour being observed or measured can change that behaviour. For example, someone might work harder on a task or be more diligent if they know they are being watched.

Social Desirability Bias

Participants might respond in a manner they believe is socially acceptable or desirable rather than how they truly feel or believe, skewing results.

Potential for Misinterpretation

Demand characteristics can lead researchers to mistakenly attribute outcomes to their manipulation when, in fact, it’s due to participants’ perceptions of what’s expected.

Threat to External Validity

If participants in an experiment behave in a way that they wouldn’t in a real-world scenario due to demand characteristics, then the results may not generalise well outside the experimental setting.

Potential Ethical Concerns

Some might argue that allowing participants to be influenced by demand characteristics, especially without debriefing them afterwards, might be misleading or manipulative.

How do Demand Characteristics Affect Participants?

Demand characteristics can affect participants in several ways:

Performance Enhancement

If participants understand what is expected of them, they might try to perform better than they would under normal or uninfluenced circumstances.

Conformity to Expectation

Participants might alter their behaviour to match what they perceive as the experimenter’s expectations, whether beneficial or detrimental.

Evaluation Apprehension

Participants might be concerned about being judged by the experimenter, leading them to behave in ways they believe are socially desirable or acceptable.

Hypothesis Guessing

Suppose participants guess the purpose of the study or the hypothesis being tested. In that case, they might change their behaviour either to confirm the hypothesis or, in some cases, try to disprove it.

Placebo Effect

In medical or clinical research, if participants believe they are receiving treatment (even if it is a placebo), they might exhibit changes in their condition based on the mere belief that they are being treated.


The mere knowledge of being observed or measured can alter a participant’s natural behaviour.

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How to Reduce Demand Characteristics 

Here are the ways to mitigate the effects of demand characteristics:

Blind Design

Keep participants uninformed about the study’s true purpose or the hypothesis being tested. In double-blind studies, even the experimenters interacting with participants don’t know certain crucial details, ensuring they don’t accidentally convey expectations.

Use of Control Groups

Having a control group can help distinguish the effects of the independent variable from those of demand characteristics.

Use of Deception

Sometimes, researchers provide a cover story or misleading information about the study’s purpose to prevent participants from guessing the true nature of the experiment. However, the ethical considerations surrounding deception must be considered, and participants should be debriefed afterwards.

Unobtrusive Measures

Using measures that don’t draw attention to what is being observed or tested can help reduce reactivity.

Post-Experimental Questionnaires

Asking participants about their perceptions of the study afterwards can provide insights into whether they noticed or were influenced by any demand characteristics.

Naturalistic Observation

Observing behaviour in natural settings, where participants might not know they are being observed, can help get genuine and unaffected behaviour.


To sum it up, when asking, “What is demand characteristics?” one needs to recognise it as a potent influence in research settings that can alter the true outcomes of a study. By being aware of this and taking steps to minimise its effects, researchers can aim to produce results that are genuine, reliable, and representative of natural behaviours and responses. 

Whether you are a budding psychologist or just someone interested in the intricacies of human behaviour, understanding demand characteristics and their impact is pivotal in deciphering the complex world of psychological research.

Frequently Asked Questions 

Demand characteristics refer to experimental cues that signal participants how they are expected to behave. These unintentional cues can influence participants’ responses and compromise the validity of study results, as participants may change their behaviour to align with perceived expectations rather than respond naturally.

In psychology, demand characteristics refer to subtle cues or signals in a research setting that inform participants how they’re expected to behave. These cues can affect participants’ responses, potentially skewing results. Recognising and controlling for demand characteristics is vital to ensure genuine reactions and maintain the study’s validity.

  • Use double-blind procedures where participants and experimenters are unaware of the study’s purpose.
  • Employ deception or distractor tasks to hide true aims.
  • Provide standardised instructions.
  • Minimise interaction between participants and researchers.
  • Regularly assess and refine the experimental design to limit cues.

Demand characteristics can skew research findings by influencing participants’ behaviours or responses to align with perceived experimenter expectations. This can produce artificial results, reducing the study’s external and internal validity. Thus, observed effects might not represent genuine participant reactions but rather their attempts to conform to the study’s implied desires.

Yes, demand characteristics can act as confounding variables. They introduce external influences that may affect participants’ responses in an experiment. If not controlled for, they can mask or exaggerate the true relationship between the independent and dependent variables, making it unclear whether observed effects are genuine or influenced by these characteristics.

Demand characteristics threaten internal validity. Internal validity pertains to how well an experiment is done, especially whether it avoids confounding factors. If participants change their behaviour due to demand characteristics, it becomes unclear if the independent variable caused the observed change or is due to participants’ perceived expectations.

About Owen Ingram

Avatar for Owen IngramIngram is a dissertation specialist. He has a master's degree in data sciences. His research work aims to compare the various types of research methods used among academicians and researchers.