New Study Says Humans Are Responsible for Puppy Dog Eyes
New Study Says Humans Are Responsible for Puppy Dog Eyes

New Study Says Humans Are , Responsible for Puppy Dog Eyes.

Are you head over heels for the sweet and soulful "puppy dog" eyes looking up at you?.

Naturally, many of us are suckers for our begging pups, but dogs weren't always so irresistibly sweet.

A recent study has found that "puppy dog" eyes are a result of breeding that started nearly 33,000 years ago.

Dogs are unique from other mammals in their reciprocated bond with humans which can be demonstrated through mutual gaze ... , Anne Burrows, professor Rangos School of Health Sciences at Duquesne University, via CNN.

... something we do not observe between humans and other domesticated mammals such as horses or cats.

, Anne Burrows, professor Rangos School of Health Sciences at Duquesne University, via CNN.

Throughout the domestication process, humans may have bred dogs selectively based on facial expressions that were similar to their own.

, Anne Burrows, professor Rangos School of Health Sciences at Duquesne University, via CNN.

Throughout the domestication process, humans may have bred dogs selectively based on facial expressions that were similar to their own.

, Anne Burrows, professor Rangos School of Health Sciences at Duquesne University, via CNN.

Dogs have more "fast-twitch" facial muscles than their genetic cousin, the wolf.

Dogs have more "fast-twitch" facial muscles than their genetic cousin, the wolf.

Researchers say these muscles allow them to mimic the facial expressions of humans.

Over time dog muscles could have evolved to become 'faster,' further benefiting communication between dogs and humans.

, Anne Burrows, professor Rangos School of Health Sciences at Duquesne University, via CNN.

Presented at the American Association for Anatomy's annual meeting, the study analyzed the facial muscles of domesticated dogs and wolves.

Researchers say they've found wolves have lower percentages of fast-versus slow-twitch fibers.

Slow-twitch fibers in the face of wolves are beneficial to their howl.

Fast-twitch fibers in the face of domesticated dogs benefit communication with humans via short, fast barks and varied facial expressions.

These differences suggest that having faster muscle fibers contributes to a dog's ability to communicate effectively with people.

, Anne Burrows, professor Rangos School of Health Sciences at Duquesne University, via CNN