Tail-wagging, face-licking, jump-in-your-lap friendliness is what dog lovers adore and cat people scorn. But like it or not, the incredible sociability of many — although not all — dogs is universally recognized. It sets dogs apart from their wild relatives.

Even the most socialized, friendly wolf is cold company compared with a Labrador retriever in full face-licking mode.

But what produces this social exuberance? A team of researchers reported on Wednesday in the journal Science Advances that the friendliness of dogs may share a genetic basis with a human disease called Williams-Beuren syndrome.

Humans with this developmental delay, caused by mutations in a region of genes, show a variety of symptoms that include intense and indiscriminate sociability.