The bonobos turned out to be even more selective than chimp groups, who have a notoriously strict hierarchy. That might seem a little backwards, but it actually makes a lot of sense. In the chimp world, it's perfectly acceptable to coerce a female into having sex, and "coerce" is a pretty generous word. If you're okay with that method of persuasion, it follows that males who are lower on the ape totem pole will still be able to mate, if not quite as often as their stronger and more attractive adversaries. But bonobos are much more peaceful, so the lower-ranked fellas don't even get a chance. It's lady's choice, and when she inevitably chooses your more desirable buddy—well, too bad.