YSM Issue 90.1

cognitive science
FOCUS
ABOUT THE AUTHOR
ANNA WUJCIAK
ANNA WUJCIAK is a senior Biomedical Engineering Major in Saybrook
College. She works in Jay Humphrey's lab studying cardiovascular
biomechanics and is a member of the Women's Club Water Polo Team.
THE AUTHOR WOULD LIKE TO THANK Laurie Santos, Angie Johnston,
and Paul Holden for their time and passion for their research.
IMAGE COURTESY OF THE DOG BREED INFO CENTER
►Dingoes look very similar to dogs. Yet,
there are stark differences, both physical and
psychological, between the two species of
canines.
FURTHER READING
Smith, B. & Litchfield, C. (2010). Dingoes (Canis dingo) can use human social
cues to locate hidden food. Animal Cognition, 13, 367-376.
and error behavior, while other species are
more inclined to engage in this behavior
because they do not automatically accept
the information others have given them.
Canine independence
At the Canine Cognition Center at Yale,
professor Laurie Santos, PhD candidate
Angie Johnston, and research assistant
Paul Holden explored whether dogs displayed
overimitation. Dingoes were studied
similarly at the Dingo Discovery Center
(DDC) in Australia. Dogs were then
compared to dingoes, a closely related but
non-domesticated species, in an effort to
explore the role of domestication.
In four different trials, animals were
tasked with opening a box to retrieve the
treat inside. These boxes, which Holden
designed at the Yale Center for Engineering
Innovation and Design, were equipped
with a lever on the side and a treat underneath
a flip lid. Although the flip lid was
necessary for getting the treat, the lever
was completely ineffective. At the beginning
of each test, a human completed both
the relevant and irrelevant steps in the
process of opening the box three times
as a display for the animal. The box was
considered solved if the animal was able to
retrieve the treat.
Results showed the dogs and dingoes
filtered out the irrelevant lever action,
even though it was demonstrated to them.
With each of the four tries the test subjects
had with the box, the rate of using the irrelevant
lever decreased and the rate of
solving the box increased. This indicated
that both species of canines were learning
which actions were relevant and which actions
were not based on their own learning
experiences.
Although neither canine species displayed
overimitation, there were differences
in the two species. “Dingoes were
using the lever less than dogs,” Holden
said. “At first glance, dogs and dingoes
look quite similar, but they’re actually very
different.” Dingoes are clever problem
solvers because they are more attentive
and independent, Johnston added. Dogs
have become domesticated over time due
to their companionship with humans, and
therefore they tend to look toward their
human more often when a problem arises.
As dogs have come to rely on humans
more, they may have also become less
adept at independent problem solving,
which might explain why they used the lever
more frequently than dingoes.
A human behavior
The brain mechanism behind overimitation
is not yet well understood. Although
it is outside the scope of Santos’s psychology
lab, other researchers are exploring the
complex brain processes that control decision-making
and overimitation.
Unfortunately, outside of dogs, dingoes,
and chimpanzees, not many species have
been tested for overimitation behavior.
Dogs were selected as a species to study
specifically at Yale because they are highly
social. Chimpanzees have previously been
studied because of their high intelligence
and social tendencies. Scientists assume
that since the closest relative to the human,
the chimpanzee, does not display
this behavior, it is human specific. The absence
of overimitation in chimpanzee behavior
also indicates that humans evolved
this trait sometime within the last seven
million years since our species diverged.
Corvid species, which include birds and
crows, may be valuable to explore next,
as they are also very intelligent creatures.
“Most animals exhibit innate behaviors
that they’ve developed over many years
of evolution,” Johnston said. For example,
think of squirrels who bury nuts every
winter.
If not from overimitation, how do other
species pass on information? Johnston
explained that animals learn through observation,
as opposed to the intentional
instruction method of passing information
like humans. Some information, such
as locomotion, is instinctual. “It’s not that
other animals can’t imitate, it’s just that
they only do it when they need to, whereas
humans tend to do it much more often
than necessary. Animals are better at
prioritizing the information they really
need,” Johnston said. While humans have
complex technology and intricate cultural
practices, other species have more basic
tasks that they can typically address on
their own. Our species is the only one
with a culture that forces us to rely on others.
There are two general hypotheses about
the driver of human overimitation. The
first is that humans can’t help but overimitate.
The second is that humans assume
that the actions they observe are the culturally
appropriate way to behave. “My
thoughts are that it’s really a combination
of both of these hypotheses that cause humans
to overimitate,” Santos said.
Overimitation, for better or worse,
seems to be a distinctly human behavior.
It assists our species to pass on complex
cultural information and maintain a high
degree of advanced technology. It certainly
appears that overimitation is one of the
reasons that humans differ so greatly from
all other species.
www.yalescientific.org
December 2016
Yale Scientific Magazine
19