Emotional Contagion From Humans to Dogs Is Facilitated by Duration of Ownership.

Maki Katayama,Toshitaka Yamakawa,Kazutaka Mogi,Koichi Fujiwara,Kazushi Ikeda,Takefumi Kikusui,Kensaku Nomoto,Miho Nagasawa,Takatomi Kubo

doi:10.3389/fpsyg.2019.01678

Abstract

Emotional contagion is a primitive form of empathy that does not need higher psychological functions. Recent studies reported that emotional contagion exists not only between humans but also among various animal species. The dog (Canis familiaris) is a unique animal and the oldest domesticated species. Dogs have coexisted with humans for more than 30,000 years and are woven into human society as partners bonding with humans. Dogs have acquired human-like communication skills and, likely as a result of the domestication process, the ability to read human emotions; therefore, it is feasible that there may be emotional contagion between human and dogs. However, the higher time-resolution of measurement of emotional contagion between them is yet to be conducted. We assessed the emotional reactions of dogs and humans by heart rate variability (HRV), which reflects emotion, under a psychological stress condition on the owners. The correlation coefficients of heart beat (R-R) intervals (RRI), the standard deviations of all RR intervals (SDNN), and the square root of the mean of the sum of the square of differences between adjacent RR intervals (RMSSD) between dogs and owners were positively correlated with the duration of dog ownership. Dogs’ sex also influenced the correlation coefficients of the RRI, SDNN, and RMSSD in the control condition; female showed stronger values. These results suggest that emotional contagion from owner to dog can occur especially in females and the time sharing the same environment is the key factor in inducing the efficacy of emotional contagion.

Highlights

Emotional contagion is a primitive form of empathy and does not need higher psychological functions such as theory-of-mind and perspective taking
We examined the emotional contagion between humans and dogs by accessing the autonomic responses
It was found that emotional contagion can be transferred from the owner to the dogs, and the efficacy of the emotional contagion was depending of the duration of the time sharing with dog and owners

Summary

Introduction

Emotional contagion is a primitive form of empathy and does not need higher psychological functions such as theory-of-mind and perspective taking (de Waal, 2009). Co-housing for more than 3–4 weeks were needed to show emotional pain contagion in mice dyads (Langford et al, 2006; Jeon et al, 2010) This theoretical hypothesis has not been well documented using animal models. One example was a rat experiment that did not provide direct evidence for emotional contagion but did show that pair-housed rats exhibited helping behavior after co-housing more than 2 weeks In this example, sharing the same environment was an important factor in inducing helping behavior even the partner rat was genetically different strains (Ben-Ami Bartal et al, 2011; Bartal et al, 2014). There is no genetic relatedness between dogs and owners

Methods

Results

Conclusion