Human Pheromones: Releasers or Primers

Abstract

Historically, insect pheromones and the responses to them were thought to have a high degree of specificity and a considerable degree of genetic programming. These include overt displays of attraction and copulation mediated solely by chemical signals, which have been described as releaser effects on behavior. More subtle neuroendocrine effects, i.e., primer effects, resulting in changes in reproductive cycle-length, timing and success, have been demonstrated in mammals. Humans have potential sources of chemical signals and a sensory system to receive them. Recent studies suggest the presence of a vomeronasal organ (VNO) in humans; however, other observations suggest only scant evidence for the presence of an anatomically complete VNO with connections to the central nervous system (CNS).

One would not expect to see observable “releaser” pheromone effects in humans, which are primarily behavioral and immediate. Despite the lack of evidence, numerous fragrances, or additives to fragrances, whose advertisements perpetuate the myth that an odor can make one irresistible to members of the opposite sex, have been, or are being sold. Studies conducted over the past two decades present evidence that humans emit primer pheromones, which can alter the length and timing of the menstrual cycle. The human axillae is a likely source of these chemosensory signals. The molecular identity and chemoreceptive and endocrine pathways by which they operate remain to be elucidated.