In addition, models can also predict when will the effects of this phenomenon, the team has published its allazgos in an article in the August 30 issue of the scientific journal "Evolution and Human Behavior."

In the article, titled "Understanding the placebo effect from an evolutionary perspective," Dr. Pete Trimmer explains how the theoretical work of psychologist Nicholas Humphrey, was used as a starting point for this study.

The placebo effect has been a mystery to the scientific community for a long time. This occurs, for example, when a patient is given a sugar pill, and is told that it is actually a drug to treat the condition being treated.

The patient usually experiences relief associated with that drug, but find no trace of the active chemicals in your body. One of the main reasons is that the placebo works on the basis of the beliefs of patients.

An old question is related to the problem why humans deserrollamos a mechanism for self-healing faster and effective over millions of years of evolution. The team from the University of Bristol has created models to examine the "balance between the cost and benefit of the immune response when the body is faced with a health problem."

The main conclusion from the research is that the placebo effect is regulated by the patient's expectations.

Some time ago, Humphrey suggested that contain immune system activation is sometimes good for health, because there is no clear way for our body's natural defenses to know, in advance, the immunological risks that might have to face. Consider also that during the thousands of years of evolution, risks, really important, to which human beings were faced starvation or eaten by other animals.

"The placebo effect reduces guesswork about when to take action. Wait a pill" useless "before acting is not the best method, but still the overall sensitivity to signals adaptable, it is logical that evolved organisms respond to the placebo effect "according Trimmer.