Dogs Can Smell Human Stress.... And It's Depressing

Dogs sniff out the smell of human stress, leading them to make more ‘pessimistic’ choices.

Researchers tested how human stress odors affect dogs’ learning and emotional state.

The team used a test of ‘optimism’ or ‘pessimism’ in animals, which is based on findings that ‘optimistic’ or ‘pessimistic’ choices by people indicate positive or negative emotions, respectively.

Researchers discovered that stress smell made dogs slower to approach a new bowl. These findings suggest that the stress smell may have increased the dogs’ expectations that this new location contained no food, similar to the nearby empty bowl location.

Researchers suggest this ‘pessimistic’ response could possibly be a way for the dog to conserve energy and avoid disappointment.

The team also found that dogs continued to improve their learning about the presence or absence of food in the two trained bowl locations and that they improved faster when the stress smell was present.