POPSCI.COM/ SPRING 2020 101tested wolf-human and dog-human cooperation
partners, the pattern became clearer. Wolves
aren’t afraid to take the lead, while dogs hang
back and wait for a human to make the first move.
These unexpected findings led Marshall-Pescini
toward yet a third theory of self-domestication:
Maybe the shift wasn’t a new social skill or expres-
sion of love, but rather a novel conflict-management
strategy. Humans probably would’ve killed bold,
assertive wolves as a threat. But they might have
tolerated deferential, avoidant proto-dogs skulking
around the camp, hoping for a handout. (Aggressive
varieties are probably a recent phenomenon, the re-
sult of dog fanciers in the 18th and 19th centuries
who created nearly all modern breeds.)
Her group is looking at village dogs to under-
stand more about canine social structure and how
they respond to humans. Compared with our pets,
these free-ranging animals are probably far more
similar to the early dogs that were their long-ago
ancestors—some friendly, some shy, all of them
in an uneasy, ambivalent relationship with the
hairless apes they rely on to survive.
LURKING AROUND THE EDGES OF THIS
research, like some wolf sneaking beyond the
campfire, is the idea that we too may have do-
mesticated ourselves. That’s one reason Hecht
hopes to find a signature of tameness; if she does,
she can look for the same pattern in the brains of
house cats as compared with wild ones, and in our
gray matter in contrast to apes. Anthropologist
Hare’s version of this account of human origins,
“survival of the friendliest,” posits that just like
dogs, we became more trusting and tolerant of one
another in our long-ago past, which in turn allowed
us to develop superskills in communication—
language is one obvious example.
The notion of human self-domestication has
bumped around at least since Darwin’s time,
but today there’s actually evidence, points out
primatologist Richard Wrangham of Harvard’s
Department of Human Evolutionary Biology.
In addition to our unusual (for primates) tol-
erance of strangers and our long adolescence,
we show some of the physical traits associated
with domestication syndrome. Compared with
our hominid relatives, we have shortened faces
and smaller teeth. In 2014, Wrangham and col-
laborators even proposed a possible biological
mechanism in neural crest cells, which help shape
many of those body parts during embryonic
development. The implication, as implausible as
it might seem in these times, is that our species
evolved to get along peaceably with one another.
In December 2019, a European group found that
the gene BAZ1B, located in the Williams- Beuren
region, influences facial shape by directing
such cells. It could explain part of the human
self- domestication story, Wrangham says.
Back in Hecht’s lab, a new volunteer named Coda
runs through his tests. (Coincidentally, he’s also a
Boston terrier.) For one task, McCuistion places
a treat on the floor, says, “No! Don’t take it!” and
then closes her eyes. Dogs know what eyes closed
means, so at this point, most snatch the treat. Not
Coda. As his owner points out, he’s always a very
good boy. He sneaks a look at it, licks his lips, then
stares glumly into space, waiting, deferring, and
avoiding conflict, as is his dogly destiny.
Over on the other side of the one-way mirror,
the humans are entirely absorbed in this drama.
“Goooood boy,” someone says. Even after
McCuistion finally gives him permission to eat
the snack, he still stands there looking sadly at
her. A chorus erupts in the waiting room: “C’mon,
Coda, take it!” We can all see his desire, feel his
restraint. It’s enough to make you wonder who,
exactly, evolved to read whose mind.
To look upon a dog, even through a one-way mir-
ror, is to look upon our own species as well—what
it takes to live in harmony, to understand one an-
other, to replace fear and aggression with love and
loyalty. Perhaps that is why dogs are so thoroughly
delightful. They are a living reminder of a better
version of ourselves. His afternoon of psychologi-
cal prodding over, Coda takes the treat and shakes
himself. His owner comes into the room, and he
leaps up onto her lap, panting happily, staring
deep into her eyes as she looks directly into his.DOGS: A LOVE STORY