You don't need to administer a placebo to elicit a placebo effect: Social factors trigger neurobiological pathways to enhance sports performance.

The placebo effect is traditionally viewed as a positive outcome resulting from a person's belief that an inert substance is in fact an active drug. In this context, it is often viewed as an intrapsychic phenomenon. However, most placebo effects reported in scientific research result from social interactions. These might be explicit, such as the description and administration of a treatment by a practitioner, or less explicit, for example, the recipient's perceptions of the practitioner's credibility, expertise, or confidence. On this basis, placebo effects are arguably social in origin. Many phenomena in sport are likewise social in origin, from the facilitation effects of a home field crowd or a cohesive team, to anxiety induced by an expert opponent or perceived underperformance. Such social effects have been the subject of research not only in social psychology, but also in experimental physiology. Emergent research in cognitive and evolutionary anthropology suggests that these social effects can be examined as a form of placebo effect. This suggestion is not a speculative position predicated on social and placebo effects sharing similar environmental cues and outcomes, but one based on a growing database indicating that drug, placebo, and social effects operate via common neurobiological mechanisms. In this paper, we examine the theoretical and empirical overlap between placebo and social effects and describe emergent research reporting specific brain pathways activated by socio-environmental cues as well as by drugs and placebos. We do so from three perspectives: the competitor, the teammate, the researcher. [ABSTRACT FROM AUTHOR]