The new study, published July 19 in Scientific Advances, found that dogs have a few gene mutations similar to ones in humans with Williams-Beuren syndrome. One of the symptoms of this developmental disorder is a complete lack of social inhibition, which makes the person particularly outgoing and trusting.

“We’re not saying we have found the mutation that controls sociability,” Bridgett vonHoldt, one of the authors of the study, told The Verge. “The story is far from complete.”