Research clarifies the mechanisms of human-dog interaction.

Emotional connection enhances interaction in human relationships. Emotional synchronization in the interaction between a child and a parent is essential for affective attachment. The relationship between a dog and its owner is also based on attachment, but little is known about its physiological mechanisms.

In a study conducted at the University of Jyväskylä, at the Department of Psychology and Jyväskylä Center for Interdisciplinary Brain Research, it was found that the heart rate variability of a dog and its owner are interconnected during interaction.

Heart rate variability, in other words, the variation in the heartbeat intervals, indicates the state of the autonomic nervous system. High heart rate variability is associated with a state of relaxation and recovery, while low heart rate variability indicates stimulation or strain, such as stress during an exam or sports performance.

In this study, published in Scientific Reports, the owner's high heart rate variability was connected to the dog's high heart rate variability, and vice versa. In addition, the physical activity levels of a dog and its owner mutually adapted to each other during the study.

Different connections for activity and heart rate variability

The connections of heart rate variability and activity levels between a dog and its owner were monitored during specific interaction tasks. Both heart rate and activity level were interconnected between dogs and their owners, but at different times.

During free-form resting periods, the owner's high heart rate variability was connected to the dog's high heart rate variability. In other words, when the owner was relaxed, the dog was also relaxed. Moreover, the owner's and dog's activity levels were similar during the given tasks, such as playing.

Although it is known that physical activity has an impact on heart rate, the strongest connections of these variables between dog and owner were found in different situations and do not fully explain each other. This suggests that the connection in heart rate variability reflects the synchrony of emotional state rather than of activity levels.

"The interconnection in heart rate variability between the dog and its owner during resting periods may be explained by the fact that in those instances there were no external tasks, but the counterparts could react more to each other's state in a natural way," says doctoral researcher Aija Koskela.

The study also investigated various background factors for the interconnection of the heart rate variability of the dog and its owner. Bigger dogs had higher heart rate variability. In addition, the dog's high heart rate variability was also explained by the owner's negative affectivity, a temperament trait that reflects the person's tendency to become easily concerned about negative things. This type of owner tends to develop a strong emotional bond with the dog, and therefore the shepherd dogs of this study possibly had a higher sense of safety with these owners.

The dog also influences the owner

A surprising finding in the study was that the owner's heart rate variability was best explained by the dog's heart rate variability, even though also the owner's activity level and body mass index, which are known to impact heart rate, were taken into account in the analysis.

"We exceptionally investigated both a dog's and its owner's heart rate and activity level simultaneously, whereas previous studies have commonly focused either on the human's or the dog's perspective," says the leader of the study, Academy Research Fellow Miiamaaria Kujala. "The challenging research setting gives a better opportunity to investigate interactive aspects."

This study indicates that the emotional states of dogs and their owners as well as the reactions of their nervous system become partially adapted to each other during interaction. The same mechanisms that strengthen human affective attachment also seem to support the relationship between a dog and its owner. This study deepens our understanding about the interaction between species and about the meaning of the emotional connection between dogs and humans.

The study involved altogether 30 voluntary dog owners with their dogs. The dogs represented breeds refined for cooperating with humans, such as sheep dogs and retrievers. The research findings are in line with previous studies, which have suggested that breeds selected for cooperation are particularly sensitive to react to their owners' behavior and personality traits. Next, the project will seek to shed light more specifically on the influential mechanisms involved in this phenomenon.

More information: Aija Koskela et al, Behavioral and emotional co-modulation during dog–owner interaction measured by heart rate variability and activity, Scientific Reports (2024). DOI: 10.1038/s41598-024-76831-x

Journal information: Scientific Reports

Provided by University of Jyväskylä