Dogs may have earned the title of our best friends through their interactions with humans，but now researchers say these social skills could be present shortly after birth rather than being learned. 

To better understand the role of biology in dogs' abilities to communicate with humans, the researchers studied 375 eight-week-old service dogs. They looked at how these dogs performed in a series of tasks designed to measure their communication skills. The puppies were still living with their littermates(同窝出生者) and had not been sent to live with a volunteer puppy raiser，making it unlikely that they had learned about his or her behavior.

In the first task，a person hid a treat beneath one of two overturned cups and pointed to it to see if the puppy could follow the gesture. Since dogs are good at using noses to find things，a treat was also taped to the insides of both cups. In the second task，puppies watched as the researchers placed a yellow block next to the correct cup，instead of pointing to indicate where the puppy should look for the food. 

The third task was designed to observe puppies' tendency to look at human faces. There searchers spoke to the puppy in a voice people sometimes use when talking to a baby. They then measured how long the puppy fixed a stare on the human.

In the last task，researchers sealed a treat inside a closed container and presented it to the puppy. They then measured how often the puppy looked to the human for help in opening the container. 

The study found that while many of the puppies were responsive to humans' physical and verbal cues，very few looked to humans for help with the unsolvable task. Researchers said, "This suggests that while puppies may be born knowing how to respond to human-initiated communication，the ability to initiate communication on their own may come later. "The next step will be to see if specific genes that may contribute to dogs' abilities to communicate with humans can be identified.