In much of the research concerning the placebo phenomenon, the idea that placebo effects may vary in strength depending on a patient's personal characteristics or traits has been investigated. Findings regarding possible personality differences in placebo response, however, are conflicting and non-systematic. In this article a new theoretical attempt to explain the placebo phenomenon is offered. The authors postulate that the power of the placebo effect is moderated by the extent of use of cognitive structuring, which in turn is influenced by the interaction between the individuals' level of need for cognitive closure and their ability to achieve this state. To test this assumption, a study using a placebo with information given to participants that this “medicine” improves mood and well-being was conducted. The results obtained fully support the predictions. The impact of this finding both for the theoretical understanding and practical implications of the placebo effect is presented.
- Ability to achieve cognitive structure
- Cognitive structuring
- Individual differences
- Need for closure
- Placebo effect