Effects of observational learning on placebo responses, or why sham remedies seem to work so well

Many companies selling ineffective treatments for painful conditions manage to attract a large customer base by showcasing testimonials from satisfied customers. Recent research suggests that these individuals might genuinely benefit from hearing others express positive experiences.

A study published in the journal Pain, titled “Learning pain from others: a systematic review and meta-analysis of studies on placebo hypoalgesia and nocebo hyperalgesia induced by observational learning” explores the impact of observational learning on placebo and nocebo responses.

Placebo hypoalgesia refers to when a fake treatment (placebo) reduces pain, while nocebo hyperalgesia is when the placebo actually increases pain. Learning processes, such as classical conditioning and operant conditioning, have been shown to play a role in these effects. Verbal suggestions and observational learning from others also influence placebo and nocebo responses. However, the magnitude of these effects can vary depending on the specific learning process used.

This meta-analysis of 17 studies showed that observational learning can effectively modulate pain and pain expectancies. However, the magnitude of these effects varies across studies. Observing a model in person resulted in larger effects compared to observing a videotaped model. The analysis also suggested that placebo effects can be induced through observational learning, but nocebo effects were not consistently observed. Empathy, specifically the empathic concern component, was found to be associated with the magnitude of observational learning effects.

The article concludes that observational learning can indeed influence pain experience and pain expectancies. Further studies possibly could lead to methods to enhance the treatment effects of proven therapies.