For thousands of years, humans have bred dogs for traits such as slender bodies and sheep-herding abilities. Now it turns out that breeders have also shaped canines’ brains.
When Erin Hecht at Harvard University in Cambridge, Massachusetts, and her colleagues studied brain scans from 62 dogs across 33 breeds, they found that brain structures varied markedly between breeds. These differences did not relate solely to the dogs’ brain or body sizes, nor to their skull shapes; instead, particular variations were associated with specific activities, such as hunting by scent, or guarding.
The team also examined the brain areas that varied the most across breeds. That analysis identified six brain networks — each composed of multiple regions of the brain — that the researchers suspect are involved in tasks from social bonding to movement.
Variations in these brain networks were linked to specific breed characteristics: for example, brain regions involved in movement and navigation were bigger in dogs bred for coursing, such as Greyhounds, than in dogs bred for companionship, such as the Maltese.