Scientists say dogs can smell each other’s emotions, and react differently to joy or stress

It is common knowledge that the sense of smell in dogs is phenomenal. However, scientists are discovering that the ability of a dog to sniff out something does not revolve only around finding food, marking its territory, or recognizing another dog physically. According to a 2026 article published by Scientific Reports, it was discovered that the smell of happiness, stress, or peace in another dog may induce different behavioral reactions in the dog.

The experiment used 43 dogs who were exposed to odor samples taken from another set of dogs while in different emotional conditions. Scientists discovered that the dogs reacted to the emotional odors differently based on whether they were experiencing good times or bad times. The reason the discovery is important is that dog communication uses a much more emotionally rich chemical language than we know. According to the scientific reports, the dogs' behaviors were not based on their ability to sense differences in odors, but how they interpreted the smells.

Stress-related odors triggered visible behavioral changes

One of the most important results from this research came to light when it was found that dogs tend to stick close to their owners whenever they smell stress odors emitted by an unfamiliar dog. Such behavioral tendency has something in common with the emotional contagion phenomenon, which is characterized by the ability of one individual to indirectly influence another through emotional states.

This finding shows that the power of odor does not seem to be limited merely to the transmission of information between individuals, but also to the possibility of changing their behavior as well. It should be noted that there has been some discussion about the same issue in National Geographic: it claims that dogs can be influenced by emotional cues from both humans and their conspecifics. In addition, dogs are known for relying more on smells than humans to perceive their social environment. According to Encyclopedia Britannica, smelling gives dogs a chance to understand something about another individual's identity, health, and social status.

Dogs may experience a rich emotional world humans cannot smell directly

Dogs are now known to use smell in their communication along with sound and body language. A study published in Frontiers in Behavioral Neuroscience suggests that dogs have specialized brain systems that enable the rapid, efficient processing of scents with social value. The development of such brain systems in dogs may have occurred due to the evolutionary benefit provided by chemical communication in social animals. Scent is invisible, persistent even if the source animal is long gone, and very informative in nature.

Canines are also known to be very sensitive to human emotional odors. As PetMD reports, previous studies showed that dogs react differently to the smell of human fear than to the smells of happiness and joy. The ability of dogs to react to human emotions via smelling can help to clarify why they tend to be very sensitive to any signs of human stress or worry even before visual signals become apparent. The general meaning of the research conducted by Albuquerque et al. is that canine sociability and intelligence may rely heavily on sensory stimuli that go unnoticed by humans. Canine reactions to such smells are much more complex than an instinctive response to specific chemical stimuli. The dogs may constantly evaluate their environment by reading human emotion from the chemical composition of the surrounding atmosphere. This new discovery helps to reconsider the whole notion of canine communication.