Wondering is a series of random questions answered by Harvard experts. For the latest installment, we asked the human evolutionary biologist Erin Hecht, whose research focuses in part on neural and behavioral variation in domestic canine breeds, if your dog would care if you dropped dead.

Yes. Dogs have behavioral and circulating hormone responses to the presence or absence of their owner — and in interacting with their owner — that parallel what we see when humans interact with other humans with whom they share a bond: close friends, family members, and children. That suggests that biological correlates of the human-animal bond are similar — at least in some ways — to human-human bonds. And we know that humans get very distressed if someone they care about and have a close bond with dies. That’s one line of evidence. Another is that, phenomenologically, we can see examples of dogs that show evidence of distress when they’re separated from their owner even for a short period of time. When the owner goes to work, a lot of dogs have separation anxiety. Or if the owner does die, then dogs commonly exhibit distress that can take the form of destructive behavior or something that might look like reduced activity levels — what depression looks like in humans.

Erin Hecht.

"Dogs are a really unique window on how brains change across generations when there’s selection pressure on behavior," said Hecht.

Kris Snibbe/Harvard Staff Photographer

One thing we don’t know is to what extent biological bonding mechanisms within a group of wolves are similar to the mechanisms that support bonding between dogs and humans. Another thing we don’t fully understand is to what degree different dog breeds might have different patterns of bonding with humans. It seems like a reasonable hypothesis. Some breeds of dogs have been selected for cooperative working behaviors with one individual human — really one-on-one cooperation. Examples of that could be border collies, Australian shepherds, and other livestock herding dogs that interact closely with a human handling livestock. Other breeds don’t have that cooperative working arrangement with a single human. A livestock guardian dog seems to form strong social bonds with the livestock rather than with the human. And then there are other breeds of dogs that have been developed for human companionship. It’s possible that they might show different patterns of bonding, maybe less with one person and more with an entire household — but that’s speculation. Aside from genetic differences across breeds, individual dogs’ histories of positive interactions with individual people must also play a big role.

From the basic science perspective, I think dogs are a really unique window on how brains change across generations when there’s selection pressure on behavior. We have all these different breeds that have been selectively bred for different behavioral profiles, different types of cognitive abilities, different skills, and so forth. And there’s nothing else really like that in the animal kingdom. Studying them is a way for us to understand brain evolution in a more precise way than we can get from studying any other species. I think we’re at a point in dog research where we’re just starting to get empirical evidence of things that people who have interacted with dogs take as a given. For example, there were a few papers over the past few years establishing that dogs experience jealousy, and I think anybody who’s ever had more than one dog in their house at once knows that that happens. And this question — whether dogs would care if their human dies — is along the same lines. But it’s still important to get that empirical validation and not just go off of our gut understanding of how their minds are working.

Also in the Wondering series

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Brain scientist explains earworms

When will a robot write a novel?

Computer scientist launches new series

Should married couples live apart?

Separate takes from husband-and-wife psychiatrists on distance, drift, and how to stay connected