Calvi · Brain and behavior 2020 · systematic review · n=?

The scent of emotions: A systematic review of human intra- and interspecific chemical communication of emotions.

Level 1 - systematic review of randomized trials

Systematic review of experimental studies on emotional chemosignaling

PubMed 32212329 · doi:10.1002/brb3.1585 · record verified 2026-08-26

What was done

The authors conducted a systematic literature review evaluating the role of human emotional chemosignals (derived from axillary odors and sad tears) in human communication and their effects on animal behavior. Specific databases, search dates, screening criteria, and study counts are not reported in the abstract.

What was found

The abstract reports no numerical values, effect sizes, or statistical metrics. Qualitatively, emotional chemosignals from fear, happiness, and sad tears were reported to affect receivers' social interactions, danger detection, risk-taking behavior, social aspects of eating, and performance under stress. Human chemosignals also influenced behavioral and stress responses in domestic animals, specifically dogs and horses.

Why it matters

This review synthesizes evidence that human olfaction conveys emotional states beyond fight-or-flight reactions—including positive emotions like happiness—and can cross species boundaries to influence animal behavior.

Limits

The abstract provides no sample sizes, number of included studies, statistical results, or risk-of-bias appraisals. Details regarding how chemosignals were collected, controlled, or standardized are omitted in the abstract.