When a canine companion wants an extra treat, one glance of those endearing puppy-dog eyes is all it takes. Now, scientists suggest domesticated dogs may have evolved extra facial muscles to win people over with their adorable expressions.

Humans may have contributed to the heart-warming look through thousands of years of selective breeding for the animated faces, a statement explains. Presented at the Experimental Biology 2022 Meeting in Philadelphia, the preliminary research offers a deeper look at how dogs communicate with us.