Memory in many animals, dogs included, has a lot more in common with human memory than we once thought.
Studying the cognitive abilities of nonhuman animals, dogs included, has never been easy, primarily due to the fact we can’t truly know what these animals are thinking. Another major problem is that people are very good at reading too much into the gestures of our companions.
Types of memory
It’s also important to distinguish between the different types of memory out there. Semantic memory is the kind that allows us to recall dry facts and knowledge about the world that we’ve previously learned. Most animals and especially mammals are thought to possess semantic memory; in dogs, it lets them remember what to do when their owner says, “Stay!” (assuming they’re successfully trained, at least). But the ability to remember and replay our personal life events and experiences—the experiences that inform our behavior in the future—that’s known as episodic memory.
In decades past, some scientists argued that nonhuman animals aren’t capable of episodic memory, perhaps because they lack the sort of self-awareness present in humans. But more recent research has started to take a new look at this type of memory in canines.
A 2016 study from a team in Hungary, found that dogs can watch their owner carry out an action, then mimic that same action when prompted to do so via a specific command (in this case, “Do it!’). While this might look like a typical example of training, the researchers also demonstrated that the dogs could replicate an owner’s actions at a moment’s notice, when the owners shouted “do it” during a different task. For dogs to pull this off, the researchers argued, they would need to remember witnessing someone else’s movements, even when not explicitly trained to, then work out how to perform those same movements with their bodies—a complex feat of cognition indicative of having episodic-like memory.
The same team of researchers published another study in 2020. This time, they trained dogs to repeat certain actions of their own with a specific command. Then they had owners unexpectedly ask their dogs to repeat other actions, including those performed spontaneously in everyday situations, which the dogs managed to do very well.
These and other studies, as is often the case with animal behavior research, tend to be based on small sample sizes. Scientists have also only been able to test for specific aspects of cognition tied to episodic memory, not definitively show that dogs have it (after all, dogs can’t talk to us). Dog memory is certainly different in important ways from human remembering as well. Other research has found that dogs and other nonhuman animals tend to have a much shorter memory span in general compared to us.
Of course, there are plenty of stories of that make the case for sustained dog memory even more compelling. People have told numerous anecdotes of dogs waiting for their owners to come home or to continue going to greet them at the local train station long after their human has died or dogs regularly visiting the gravesites of their beloved owners.
Dogs might not remember quite like humans. But the bonds we make with each other do appear to be unforgettable for both parties.
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