Resentful demoralization is an issue in controlled experiments in which those in the control group become resentful of not receiving the experimental treatment. Alternatively, the experimental group could be resentful of the control group, if the experimental group perceive its treatment as inferior.
They may become angry, depressed, uncooperative, or non-compliant

Compliance (medicine)

In medicine, compliance describes the degree to which a patient correctly follows medical advice...

. This may lead to significant systematic differences in the outcome of the control group, obscuring the results of the study and threatening their validity

Validity (statistics)

In science and statistics, validity has no single agreed definition but generally refers to the extent to which a concept, conclusion or measurement is well-founded and corresponds accurately to the real world. The word "valid" is derived from the Latin validus, meaning strong...

.

External links

• Resentful Demoralization in Encyclopedia of Statistics in Behavioral Science. (subscription required)