We’ve all seen those fun photos of owners and their dogs and laughed at how they look alike.
What is it? Is it that people with jowls are attracted to Bulldogs and women with long blonde hair are attached to Afghan hounds.Or, in the photo above the bi hair look and same color?
What is the connection?
Sadahiko Nakajima, a psychologist from Kwansei Gakuin University in Japan, set out to solve the puzzle and published his findings in a journal called Anthrozoös. This wasn’t Nakajima’s first stab at it. In prior research,Nakajima had shown that participants could match photos of owners and their dogs by facial appearance alone. People could also recognize that photos of dogs and owners that the investigators had arbitrarily coupled were fake pairs. Now he wanted to find out which facial features people use to make their bizarrely accurate judgments.
He presented 502 Japanese undergrads with two test sheets. Each sheet included 20 photo sets of dog-human pairs, showing their faces together side-by-side. To eliminate extraneous factors, the photos were very basic color headshots cropped at the shoulders and shown against a plain white background. The photos were then randomly assigned to one of those two test sheets. On one test sheet, the images included a set of 20 real-life dog-owner pairs; the other sheet featured 20 randomly matched pairs. These photo sets included an equal number of female and male human owners.
Those taking part in the test had to choose the set of dog-owner pairs that physically resemble each other. they were told, They were also randomly assigned to one of five different “masking” photo conditions. The fundamental difference among these conditions was the way in which the photo sets were presented to the judges on the two sheets: no-mask (in which the participant saw the full unobstructed faces of humans and dogs); eye-mask (the humans’ eyes were covered by black rectangular bars ); mouth-mask (the humans’ mouths were covered in this same way); dog-eye-mask (now it’s the dogs’ eyes that are covered by a black bar); or eye-only (only the thin rectangular slices of the eye regions for both human and dog are shown).
Just as in Nakajima’s earlier study, the people in the no-mask condition—that’s to say, those who saw the full faces of both the dogs and the owners—were able to identify the fake domestic bonds. It’s rather amazing, actually, to think that being asked to make a forced choice on “physical resemblance” resulted in 49 of the 61 judges (80 percent) selecting the set of images showing the real-life pairs. Those who saw the same photo sets but with the owners’ mouths concealed (mouth-mask) , well 73 percent correct). By contrast, simply covering the eyes of either the humans or dogs made the judges’ performance fall to statistically chance levels. So it’s all about the eyes.
Now go and try your own experiements in the dog park.
(Photograph to illustrate the tests : Sadahiko Nakajima)