In social research, particularly in psychology, the term demand characteristic refers to an experimental artifact where participants form an interpretation of the experiment's purpose and subconsciously change their behavior to fit that interpretation.
[1] Typically, demand characteristics are considered an extraneous variable, exerting an effect on behavior other than that intended by the experimenter.
Pioneering research was conducted on demand characteristics by Martin Orne.
Rather than giving an honest answer, participants may change some or all of their answers to match the experimenter's requirements, that demand characteristics can change participant's behaviour to appear more socially or morally responsible.
Common demand characteristics include: Weber and Cook have described some demand characteristics as involving the participant taking on a role in the experiment.