Synchrony in chronotype and social jetlag between dogs and humans across Europe

Abstract

People choosing a pet have a number of factors to consider. The important one is whether a pet can synchronize with humans in sleep timing. Chronotype reflects individual differences in sleep timing. Social jetlag referring to a misalignment of one’s own biological (internal) time compared to the social time reflects variability in sleep timing between work and free days and is considered a health risk factor. In this study, chronotype and social jetlag of dogs and people living together were assessed based on a survey carried out in Poland, Germany and Spain (N = 730; 74% female; age = 36.1 ± 12.8). Participants living with dogs informed about their own and their dogs’ sleep habits. This study demonstrates synchrony in sleep timing between humans and dogs living together. Dogs experienced less social jetlag than their owners and differences between owners and dogs were more pronounced in Poland than in Germany and Spain. Polish dogs had the lowest social jetlag amongst dogs from the three countries, suggesting a greater stability of their sleep–wake cycle and less influence of the owners’ activity on their rhythm. Chronotype of dogs was earlier than that of their owners in all countries. Spanish dogs had the latest sleep pattern, followed by German dogs, with Polish dogs being the earliest. Analyses also revealed that both chronotype and social jetlag in dogs and humans living together are correlated – the later the chronotype of the owner the later the chronotype of his/her dog. The results suggest that dogs synchronize to humans in their sleep patterns.