Facts, fallacies, fears, and frustrations with human pheromones

Area of Science:

• Human biology
• Neuroscience
• Behavioral science

Background:

• Pheromones play a variable role in primate social communication, with human pheromonal communication being particularly debated.
• The human axilla's secretions and microflora interactions create an environment analogous to scent glands in other primates.
• Understanding human pheromones requires examining axillary compounds, the vomeronasal organ's (VNO) functionality, and potential signaling pathways.

Purpose of the Study:

• To assess the likelihood of pheromonal communication in humans.
• To discuss chemical compounds from the axilla that may act as pheromones.
• To evaluate the functional status of the human vomeronasal organ (VNO) and alternative pheromone reception pathways.

Main Methods:

• Review of existing literature on human axillary secretions and their effects.
• Analysis of the vomeronasal organ (VNO) structure and function in humans compared to other mammals.
• Classification of pheromones (primers, signalers, modulators, releasers) and assessment of evidence for each in humans.

Main Results:

• Human axillary chemistry and effects on conspecifics show analogies to other mammalian pheromone systems.
• Evidence supports primer (e.g., menstrual synchrony), signaler (e.g., mother-infant recognition), and modulator effects in humans.
• The human VNO may lack critical components for typical mammalian pheromone reception; the olfactory epithelium is a potential alternative pathway.

Conclusions:

• While human pheromonal communication is plausible, especially for primer, signaler, and modulator effects, definitive proof is lacking.
• The human VNO's functionality for pheromone reception is questionable, suggesting alternative pathways like the olfactory epithelium.
• Isolation of specific human pheromones through bioassay-guided studies is necessary to elucidate their precise functions.