That puppy dog eyes have developed to control us human beings is true. But how lovely it is to find an article about evolution that actually gets the mechanism right:
In a project that has all the makings of a Roald Dahl classic, scientists have hit on an answer to the mystery of how man’s best friend got its puppy dog eyes. The sad, imploring expression held such power over humans during 33,000 years of canine domestication that the preference for dogs that could pull off the look steered the evolution of their facial muscles, researchers have said. The result is that dogs gradually acquired a new forehead muscle named the levator anguli oculi medialis, or LAOM, and have used it to deploy the doleful look to devastating effect ever since.
The underlying idea was well explained by Stephen Jay Gould in his piece upon Mickey Mouse.
Dr Juliane Kaminski, who led the research at the University of Portsmouth, said: “The findings suggest that expressive eyebrows in dogs may be a result of humans’ unconscious preferences that influenced selection during domestication. “When dogs make the movement, it seems to elicit a strong desire in humans to look after them. “This would give dogs, that move their eyebrows more, a selection advantage over others and reinforce the ‘puppy dog eyes’ trait for future generations.”
It’s isn’t that dogs developed that muscle in order to manipulate humans. It’s that dogs that could manipulate humans by having the muscle – or some proto- of it – were better cared for by humans and thus had more progeny.
Just the same as the basic idea of “baby faces” in humans in fact. As Gould explained. Humans are born pretty early in the development process, given the head size/pelvis problem. Leading to two things, firstly, the need for lots of love and attention when first born, secondly, to a distinct difference in looks between a baby and an older human. It’s not that babies developed the look to make people go “Awww, diddums!”. It’s that parents who went “Awww, diddums!” at the look had more surviving children thus won evolution. So the propensity to go “Awww, diddums” at babby looks spreads through the surviving population – those that don’t die out.
This then explaining the evolution of Mickey Mouse’s looks over the decades, as he takes on more and more of the looks of the human baby. Eye size to face size, prominence of nose and so on. Because we’re hard wired to go “Awww, diddums!” at such facial features.