It may not be such a dog-eat-dog world after all, at least among puppies. A new study has found that young male dogs playing with female pups will often let the females win, even if the males have a physical advantage.

Male dogs sometimes place themselves in potentially disadvantageous positions that could make them more vulnerable to attack, and researchers suspect the opportunity to play may be more important to them than winning.

Such self-handicapping has been documented before in red-necked wallabies, squirrel monkeys, hamadryas baboons and even humans, all of which frequently take on defensive positions when playing with youngsters, in particular.

Furry gentlemen

The gentlemanly dog behavior is even accompanied with a bow.

"We found that self-handicapping tends to occur in conjunction with play bows," lead author Camille Ward told Discovery News.

"A play bow is a signal that dogs use when they want to communicate playful intentions to a potential play partner," added Ward, a lecturer in the Department of Psychology at the University of Michigan and director of About Dogs LLC. She is also author of the forthcoming book, Relationship-Based Dog Training. Zoo babies

Ward and her colleagues studied puppy litters from four dog breeds: a shepherd mix, Labrador retriever, Doberman pincher and malamute. Play data was collected when the pups were between three and 40 weeks old. The scientists examined how the puppies played with members of their own sex as well as with the opposite sex.

Females were more likely than males to initiate play with their own sex, but that may be to stave off more vicious behavior later.

"Because adult female-female aggression, when it occurs, can generally be more intense than female-male aggression, we suggest that females may use play with other females as one way to practice threat and appeasement signals that may serve to ritualize aggression and limit overt aggression later on," said Ward, whose findings are published in this month's Animal Behavior.

Making a love connection

While males were less likely to initiate play with other males, they seemed eager to play with females, and would go to all sorts of lengths to keep the play going.

The male puppies, for example, would sometimes lick the muzzles of their opponents, giving the female a chance to bite them in a vulnerable position. They would also even completely drop to the ground from a moving, standing or sitting position, looking like a boxer down for the count.

They might lose the game in the short run, but they could win at love in the future.

"We know that in feral dog populations, female mate choice plays a role in male mating success," said Ward. "Perhaps males use self-handicapping with females in order to learn more about them and to form close relationships with them — relationships that might later help males to secure future mating opportunities."

Barbara Smuts, professor of biopsychology at Stanford University, has extensively studied play behavior in animals, including dogs. Smuts has also observed role reversal behaviors in dogs, where the dominant individual takes on a more defensive position, allowing normally submissive pooches to go on the offensive.

It appears that adult dogs who know each other well do this more often, even with members of the same sex. Dogs also may be less obsessed with winning than primates are.

"At least in some pairs, dogs seem much more willing to reverse roles than the primates for whom quantitative data exist, such as rhesus macaques and squirrel monkeys," Smuts pointed out.