from National Geographic

Centuries of breeding have reshaped dog brains—here’s how

The role for which a dog was bred—say retrieving birds—is reflected in their brain structure, according to a study of 33 breeds.

BY LIZ LANGLEY

There are hundreds of dog breeds around the world, from the teensy chihuahua to the massive Saint Bernard—all thanks to centuries of selective breeding by humans. With such a wide range of canine sizes and temperaments, it’s no surprise that, in the process, we have reshaped their brains as well as their bodies.

A new study performed MRI scans on 33 breeds and discovered how a dog was bred is reflected in their brain structure. (Read “How to build a dog” in National Geographic magazine.)

For instance, dogs bred to be small—say the lhasa apso—have round heads with similarly round brains that take up most of their skull. A larger breed like a golden retriever has a long, narrow head, and thus a more elongated brain that doesn’t fill all of the skull space.

“The biggest wow moment for me was just looking at the scans,” says study leader Erin E. Hecht, an evolutionary neuroscientist at Harvard University. “It’s really cool in science where you have a result where you don’t have to do any fancy statistics to be able to tell there’s something going on.” (Read more how humans have reordered dog brains.)

This fresh look inside the mind of dogs offers a better understanding of how breeds are hardwired, which in turn helps potential dog owners choose the right breed for their home, adds Hecht, whose study was published today in the journal Neurosci. (See our fun photo gallery of pet dogs.)

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