This is Scientific Americans 60 Second Science.

I'm Karen Hopkins.

Some parents get overly involved in their kids personal lives,

but bon-a-bo-bo-mothers take this tendency to the extreme. the getting near their future daughter-in-law. The behavior may seem overbearing, but it boosts the odds that they'll be surrounded

by grandkids.

That's according to a study in the journal Current Biology. Researchers studying wild bonobos in the Congo

noticed that some females behaved a bit like males,

fighting over fertile females and fending off some of the males who come a cordon.

That observation struck primitologist Martin Surbeck as odd.

So I just wondered, hey, what is it actually of their business?

No, it seemed most of the mammals it's just a male business

this competition over the access to females. To get to the bottom of this

unusual activity, Sorbeck, who's currently at the Max Planck Institute for Evolutionary Anthropology, got DNA samples

from the players in this melodrama.

And so it became more apparent when we did the paternity analysis and it turned out these females were mothers of some males.

And in this female-dominated society of Bonobos, the mothers acts kind of like a social

passport, allowing their sons to be more

opportunities to interact with other females.

And after the moms introduce their sons to the most desirable ladies,

they make sure the couple won't be interrupted.

As a result...

We found that males have about a three times higher likelihood to sire offspring

...