How does the smell of human fear affect dogs?

Dog owners often claim that their pets empathize with their emotions. Now it seems that this cross-species connection is real. Dogs can sense a person's emotional state and feel the same way.

Until now, science has provided evidence that dogs can see and hear signs of human emotion. But no one has investigated whether dogs can perceive olfactory cues.

Scent signals

Biagio D'Aniello from the University of Naples "Federico II" in Italy and his team tested whether dogs could detect human emotions solely from scent signals. To do this, they conducted an experiment.

Experiment

Volunteers were asked to watch videos that evoked fear, happiness, or neutral emotions. Researchers collected samples of their sweat. The researchers then presented the odor samples to domestic dogs and monitored their behavior and heart rates.

The smell of fear affects dogs' emotions

Dogs exposed to fear samples showed more signs of stress than those exposed to happy and neutral samples. They also had higher heart rates, sought contact with their owners more often, and interacted less with strangers.

Various sensory channels

We've always known that dogs gather information about their owners through various sensory channels. However, it hasn't been easy to determine which channels are activated in specific situations , explains Marta Gacsi from Eotvos Lorand University in Budapest. D'Aniello's analysis suggests that humans unconsciously take control of their dogs' emotions through the release of scents.