The placebo effect: dissolving the expectancy versus conditioning debate.

By Steve Stewart-Williams, John Podd. Psychological bulletin, 2004

692 citations recorded by the source corpus.

The authors review the literature on the 2 main models of the placebo effect: expectancy theory and classical conditioning. A path is suggested to dissolving the theoretical impasse that has long plagued this issue. The key is to make a clear distinction between 2 questions: What factors shape placebo effects? and What learning mediates the placebo effect? The reviewed literature suggests that classical conditioning procedures are one shaping factor but that verbal information can also shape placebo effects. The literature also suggests that conditioning procedures and other sources of information sometimes shape conscious expectancies and that these expectancies mediate some placebo effects; however, in other cases conditioning procedures appear to shape placebo effects that are not mediated by conscious cognition.

Subfields: Cognitive Neuroscience, Health Information Management

View Paper: https://www.semanticscholar.org/paper/e8fb1e7a4b4a511bd4465b077a06591ed615f76e

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Cognitive Neuroscience

1. Maryanne Garry
2. Irving Kirsch
3. K. G. Karahalios
4. Motahhare Eslami
5. R. Michael
6. Mark Chaves

In Health Information Management

1. Mark Chaves

Citations in the corpus

• Placebo Effects: Biological, Clinical and Ethical Advances (2010, neutral): “Classical conditioning mechanisms have been demonstrated in both animal (30-32) and human studies (27,28,33,34), although it has been difficult to exclude any cognitive component (such as expectancy) in humans (35,36).”
• Parent Beliefs about Treatment Credibility and Effectiveness: Assessment and Relation to Subsequent Treatment Participation (2007, background): “They may impact therapeutic change directly through mechanisms previously referred to as the ‘placebo effect’ (e.g., Harrington, 1997; Stewart-Williams, 2004; Stewart-Williams & Podd, 2004 ).”
• Suggestion, Cognition, and Behavior (2012, background): “Although expectancies can develop in many ways, they are often the product of suggestion (Stewart-Williams & Podd, 2004).”
• The placebo effect: From concepts to genes. (2015, neutral): “This has been discussed at length elsewhere (Stewart-Williams and Podd, 2004).”
• The Illusion of Control: Placebo Effects of Control Settings (2018, background): “Medicine [27], psychology [56], and even marketing [54] have well established the strength and power of this effect.”
• SSSR Presidential Address Rain Dances in the Dry Season: Overcoming the Religious Congruence Fallacy (2010, background): “…belief also will connect us more effectively to other literatures, such as the medical literature on placebo effects, which work mainly through expectations (Stewart-Williams and Podd 2004), or the vast psychological literature on priming, which shows that unconscious mental states shape behavior.”