Those who say men are dogs may have it all wrong. Male puppies are particularly chivalrous when playing with female puppies, putting themselves in vulnerable positions just to keep the game going, reports a new study in Animal Behavior [pdf]. The young males may be getting a primer in female behavior, which could translate to higher reproductive success later in life. Researchers videotaped four litters of puppies from different breeds (shepherd mix, Labrador retriever, Doberman pincher and malamute) at play. Even in puppies only a few weeks old, they found a noticeable gender-split in play etiquette. Female puppies mostly sought out other females as play partners. Male puppies, meanwhile, showed less interest in palling around with other males but were especially eager to initiate play with the girls.

Even when they were at a physical advantage, males would often display submissive behavior: licking the muzzles of their female opponents or crouching low on the ground. Meanwhile, both sexes often assumed the position of a “play bow,” or front legs on the ground, rear end up in the air, to show their eagerness to play. The amount of butt-sniffing that occurred was not documented.

Image: flickr/ Gyor Kamdhar