Although Experiments Are Very Useful for Determining Cause and Effect

Although experiments are very useful for determining cause and effect, they are often difficult to conduct when studying human subjects. Human research subjects may behave differently under experimental conditions than they would usually behave because they want to please the experimenters. This phenomenon has been called ________.

A) social imitation
B) inductive reasoning
C) deductive reasoning
D) the placebo effect
E) the Hawthorne effect