Citation needed - this seems to disagree, and, more generally, I would expect the ability to learn to go hand in hand with the ability to teach.

That seems to suggest that teaching is rare among chimpanzees near the end. Regardless, I'm not a zoologist, and my model of chimps is fuzzy. It may be that someone was commenting just about male chimps and I extended that to all chimps, or that most chimps don't teach except for this variety, or a number of other options.