If you blame your dog for a rough night, a new study suggests you may want to check who moved first.
In a PLOS One study tracking 25 Canadian participants and 38 human-dog pairs, researchers found that human and dog nighttime activity was significantly correlated. But among the 61% of pairs that showed correlated activity states, human activity preceded dog activity more often than the reverse: 45% versus 18%, according to the study. Another 36% of those correlated pairs were synchronized within the same one-minute period.
That does not mean dogs never interrupt sleep. It does mean this dataset points away from the simple idea that the dog is usually the problem.
What the study found
The researchers used accelerometers and survey data to examine how humans and dogs affected each other overnight. The study found that co-sleeping, defined here as bedsharing, had no effect on human sleep duration or efficiency, and no effect on dogs' nighttime activity.
The study also found a split between measured sleep and reported sleep quality. Dog sleeping location did not affect perceived sleep quality, but having multiple dogs was associated with poorer subjective sleep. The authors said that effect showed up in self-reports, not in the objective sleep measures they tracked.
In other words, sharing a bed with a dog did not show a measurable sleep penalty in this sample, while having more than one dog was linked to people feeling like they slept worse.
What the study does and does not say
The paper describes a reciprocal relationship rather than a one-way disturbance pattern. Human and dog activity moved together overnight, and the timing analysis suggests humans often set that movement off. But the evidence here is about this study's sample and measurements, not a blanket rule for every household.
What the findings support most clearly is a narrower point: in this dataset, bedsharing did not reduce measured sleep duration or efficiency, and when activity shifts lined up between people and dogs, the human was more often first to move.
That may be mildly vindicating news for dogs everywhere, or at least for the ones who have been taking the blame.
