The tendency for people to behave differently when they know they are being studied is referred to as:

• A. The Hawthorne effect
• B. Observer bias
• C. The placebo effect
• D. Social facilitation

Answer: (A)

Verified step by step guidance

1. Understand the question is asking about a psychological phenomenon where individuals change their behavior because they are aware they are being observed or studied.
2. Recall the definitions of the given options: Observer bias refers to the researcher's expectations influencing observations; the placebo effect involves changes due to expectations of treatment; social facilitation is the tendency to perform differently in the presence of others.
3. Identify that the phenomenon where participants alter their behavior simply because they know they are being studied is known as the Hawthorne effect.
4. Recognize that the Hawthorne effect is named after studies conducted at the Hawthorne Works factory, where workers' productivity changed when they were observed.
5. Conclude that the correct term for this tendency is the Hawthorne effect, distinguishing it from the other options based on their specific definitions.