Despite decades of scientific breakthroughs and rapid technological progress, some mysteries of the human body continue to baffle doctors and researchers. Considering just how incredibly complex our bodies are, this enigma hardly comes as a surprise.
Just as some people seem to possess a “sixth sense” that allows them to anticipate events before they happen, new research suggests we might also have an innate ability to sense when death is near. Scientists have discovered that at the very moment life slips away, the body begins a rapid breakdown process. This releases putrescine — a harsh, toxic odor born from decomposition. Intriguingly, humans subconsciously detect this decaying scent, triggering an almost instinctual reaction deep within us.
Two researchers—Arnaud Wisman from the University of Kent’s School of Psychology in Canterbury, UK, and Ilan Shira from the Department of Behavioral Sciences at Arkansas Tech University in Russellville, AK—have uncovered fascinating insights about human instincts. Much like animals, humans are wired to detect certain scents and respond in ways that promote survival. This deep-rooted ability is a vital part of our species’ enduring fight for life.
In a series of revealing experiments, Wisman and Shira found that when people encounter the odor of putrescine—the chemical associated with decay—they instinctively move away. This reaction mirrors how animals either flee or prepare to defend themselves when confronted with danger. It’s a primal response etched into our biology, silently guiding us to protect ourselves even before we’re consciously aware of the threat.
“We don’t fully understand why we’re drawn to—or repelled by—someone’s unique scent,” Wisman and Shira explain. “Most of the time, we’re completely unaware of how these subtle smells shape our emotions, preferences, and attitudes.”
While it might seem unusual to think of a scent as something frightening, other researchers emphasize that smells can heighten our alertness and make us more aware of our surroundings.
Take sex pheromones, for example—natural odors produced by males or females that trigger specific behavioral responses in the opposite sex. These invisible chemical signals play a powerful role in bringing people together, subtly influencing attraction and mating behaviors. It’s just one more way scent silently shapes human connection.
“Putrescine sends a very different message than pheromones,” the researchers explain. “While sexual pheromones often evoke attraction and approach, putrescine triggers avoidance and even hostility—almost the opposite reaction.” Yet, intriguingly, humans remain unaware of this odor on a conscious level and don’t directly associate it with death or fear. It operates beneath our awareness, silently shaping our instincts and behavior.
