What is the term for when participants alter their behavior because they are aware of being part of a study?

• A. Experimenter bias
• B. Demand characteristics
• C. Confirmation bias
• D. Observer effect

Answer: (B)

The term for when participants alter their behavior because they are aware of being part of a study is demand characteristics. This phenomenon occurs when participants subconsciously modify their responses or behaviors based on their perceptions of what the study is about or what the researchers expect them to do. For instance, if participants believe that the study is testing their intelligence, they might try to perform better on tasks, even if it doesn’t truly reflect their usual performance.

This effect can significantly impact the results of a study, as it introduces a bias that may confound the true effects being measured. Recognizing demand characteristics is essential in experimental design to reduce their influence, often achieved through strategies like blinding participants to the study's purpose or using deception when ethically justifiable.

The other terms refer to different concepts in research methodology. Experimenter bias involves the influence of the researcher's expectations on the outcomes of the study, confirmation bias focuses on the tendency of people to favor information that confirms their preexisting beliefs, and observer effect describes changes in participants’ behavior when they know they are being observed, which is more specific than the broader issue of demand characteristics.