How Your Stress Affects Your Pet Dog

Recent research reveals that dogs can absorb emotional contagion from the smell of human stress, leading them to make more 'pessimistic' choices. This groundbreaking study is the first to explore how human stress odors influence dogs' learning and emotional state.

Previous evidence suggests that the smell of a stressed person can subconsciously affect the emotions and decisions of people around them. Researchers aimed to determine whether dogs experience similar changes when exposed to human stress or relaxation odors.

The Study Methodology

The research team employed a test of 'optimism' or 'pessimism' in animals, based on the principle that people's optimistic or pessimistic choices indicate their emotional state. The study involved dogs aged from eight months to ten years, including breeds such as Springer Spaniels, Cocker Spaniels, Labrador Retrievers, Braque d'Auvergne, Whippet, Golden Retriever, Miniature Poodle, and mixed breeds.

Eighteen dog-owner pairs participated in a series of trials with various human smells present. During these trials, dogs were trained to associate a food bowl in a specific location with a treat, while another location consistently had an empty bowl. Once dogs learned this distinction, they approached the treat location more quickly.

Testing Emotional Responses

To gauge the dogs' emotional responses, researchers introduced new, ambiguous bowl locations between the original two. A quick approach to these new locations signified 'optimism' and a positive emotional state, while a slow approach indicated 'pessimism' and negative emotions.

These trials were repeated with dogs exposed to no odor, as well as the sweat and breath samples from humans in either a stressed state (induced by an arithmetic test) or a relaxed state (induced by listening to soundscapes).

Findings and Interpretations

The study found that the stress smell caused dogs to approach the ambiguous bowl locations more slowly, particularly those near the empty bowl location. This response was not observed with the relaxed smell.

The findings suggest that the stress odor heightened the dogs' expectations that the new location might also lack food, mirroring the nearby empty bowl. This 'pessimistic' behavior likely reflects a negative emotional state, possibly as a strategy to conserve energy and avoid disappointment.

Implications for Dog Welfare

Interestingly, the study also showed that dogs improved their learning about the presence or absence of food in the two trained locations more quickly when the stress smell was present.

This research highlights the importance of understanding how human stress affects dogs' wellbeing, particularly in kennels, and during the training of companion and working dogs, such as assistance dogs.

Dog owners often notice how sensitive their pets are to their emotions, and this study confirms that even the odor of a stressed, unfamiliar human can impact a dog's emotional state, perception of rewards, and learning ability.

While working dog handlers have long described stress 'traveling down the lead,' this research demonstrates that stress can also be transmitted through the air.